The Psychology of Buying a Car

February 3rd, 2010 Jared Tanner 1 comment

I’m in the process of buying a larger car for my expanding family. I’ve spent more than a year researching cars and prices online. Now that I’m to the point where purchasing a car is necessary, I have been looking at cars more seriously. Last night I finally decided to go visit a local car dealer to see what they had on their lot and see what their prices were like.

I got to this dealership and was approached by a woman who had just started working there. I gave her the benefit of the doubt and believed her – she really did seem new. As she walked me over to start looking at the type of car I am interested in, we were joined by a more experienced salesman who was tagging along to make sure the new saleswoman knew what she was doing. This salesman asked how much I was looking to spend. It is not usually a good idea to reveal how much you are looking to spend because of a reason I will discuss below. However, because I was just looking (although I did not tell him that) and was not going to buy a car that night (unless they happened to have a great one for a great price), I divulged my limit. I said I was willing to spend a specific amount of money. His reply, “You know that with taxes, tags, and fees [our exorbitantly high fee - he didn't say that but their fee was exorbitant] it’ll be $X more. Is that okay?” I replied, “Yes, it is.”

I stated I was going to pay cash and that I wasn’t going to trade in my car (it’s usually best to only agree you are going to trade in your car once the final price on the other car is settled in writing; that way the dealer does not mark up the price of the new car by how much the trade-in is worth). Frank [not his real name] the salesman said, “OK, I think these cars [there were three we looked at] are probably in the ballpark of your price range but I can’t be sure until I talk with the boss and he crunches some numbers.” I look at two of the cars – they were okay but I really just wanted to see the prices. Of course, there are no prices on the cars at this particular lot. Why not? Well, when I stated that I would rather talk prices first before driving any of the cars, Frank said, “Oh, well we don’t want to go through all the time and effort to talk about price before you actually drive the car. What if you find out you don’t like it?”

I mentally rolled my eyes and said, “OK, I’ll drive this car – I haven’t driven one of them before.” I decided to play his game a little bit and see where we went. If I liked the car and it was a good price, I might purchase it (but not without having my wife view and drive it). The car looked nice – it had leather seats, a DVD player, but it was a bit older and had more miles than I wanted. Said Frank, “Oh, this is a nice car – we just got it on the lot yesterday and it’ll sell fast.”

Let’s stop. Where’s the psychology in all of this? One sales technique being used on me (and I played along) is what is called the foot in the door technique. Ask little favors or even give little rewards (in this case it was as simple as pointing out the nice leather seats and DVD player and other features) and someone is more willing to listen to you and purchase your wares because they feel obligated and a bit committed. Start small and build from there. So the goal is to get the customer in the car and – assuming they like it – they will be more willing to stick with it. The other psychology sales technique he did was create a scarce commodity – make the car seem like it was going to go quickly and you feel like you have to act quickly. I’ll get back to this is a bit.

One thing I forgot to mention – as we started looking at this particular car Frank pushed the power sliding door button and nothing happened. “I’m not very familiar with this particular car,” he said, trying to cover up the fact that the power door was in fact not working (it could be opened manually). This experience was in the context of Frank talking about how they do such a thorough inspection of all their cars and fix what needs to be fixed. Then Frank says that he has to drive the car off the lot and then we’ll switch and I can drive it. I’m thinking, “That’s new, I haven’t had a dealer require that before but I don’t shop for cars very often.” So Frank starts up the car and says, “I like to let the car warm up for a little bit before driving it, my father was a mechanic and I like to take care of my cars.” The whole time the dashboard lights are dimming and then getting brighter, then dimming and back and forth for about 10 seconds. Then the car “warms up” and we’re off.

He turns the first corner in the lot and I feel a slight clunk from the transmission – that’s a great sign (that was sarcasm). I’ll fast forward a bit – I drive the car. It’s okay but I’m not too impressed. I’m impressed more with the overall look and fit and finish than its drivability. It drove okay but I didn’t think the transmission would last long. We get back to the dealership and I’m interested in what kind of ‘deal’ he’ll offer me on the vehicle. I’m an eternal optimist so I’m thinking, “Well, if he can sell it to me for $X, I might purchase it.” $X being much, much lower than my limit is. We go into his little office (the other saleswoman is there with us the whole time. She was very nice but mostly just observing at this point.) and start the paperwork “for the quote.” Again, this is a continuation of the foot in the door technique. He was trying to get me to the point where I had put enough effort in that I would say, “OK, why not?” Frank scurried off to go talk prices with his boss.

Now one of my favorite parts of this experience. He comes back with an offer that is “almost at [my] target.” It was 11% higher than my target price. If I were less polite I would have laughed. I thought, “Is he serious?! That’s ‘almost’ my target price?” This guy is very generous (to himself) with my money. I looked at the various other fees that get added on. Their dealership fee was about 8% of the car’s price. Here’s another psychological technique he used (I don’t have a specific name for it, although I’m sure one exists) – on the paper the car had a “listed” price that was at least 25% higher than his ‘reduced’ deal for me. Stores do this a lot – put things on ’sale’ and people will buy them, even if the sale price is higher than the normal price. People see “reduced prices” or “sale” and think they are getting a good deal. Sometimes they are, sometimes they are not. Had I purchased the car (I certainly wasn’t remotely considering it at that point), I would have received a bad ‘deal’.

This salesman had a problem. He thought he was in control of the situation. He forgot that the customer is always in control unless he or she relinquishes that control. I had a firm grip on my control, he just did not realize it. I did surrender enough to keep the car buying process moving because I wanted to see where it would go. I wanted to see his ‘best deal’ for me on this car. While we were going through initial paperwork he mentioned that he had a couple coming from “[not-so-nearbyville] or was it [slightly-closer-nearbyville] tomorrow to look at and probably purchase the vehicle.” He might have been telling the truth about the matter – I like to give him the benefit of the doubt – but the whole statement was too contrived to seem real, even if it was. Once again he was trying to make the car a scarce commodity that I had to act on “tonight or it will be gone tomorrow!”

One more point about why he thought he was in control of me – I am not a rude person and I can come across as rather soft and indecisive at times. I look like an easy target. I’m sure I am in some situations – like with my daughters – but I was fully in control in this situation; I didn’t want to be rude and just stand up and leave. I said the price was still too high and I called him out on his statement that the price was “almost at my target”. Maybe in government spending but not for me. He left to talk with his boss and came back stating that in order for his boss to give me a better deal I had to sign my name to show that I was “committed” to this car – that’s just some more sales psychology. Once you start to sign things, even meaningless pieces of paper like the one I signed, you tend to feel more committed and it is harder to back down. The only thing I was committed to was not buying the car. I also was enjoying the psychology of the situation, I was a bit impressed with his sales techniques. He actually didn’t come across as pushy as other salesmen I’ve met but his techniques needed some polish. He never even found out if I really liked the car. I said it was nice and he jumped on that, he assumed he could sell the car to me. I know that is optimistic salesmanship on his part but selling is much easier if it is a car (or other thing) that the person actually wants.

His sales shortcomings were not entirely his fault, I was quite non-committal (which came across as “almost convinced to buy”) about the process because I really just wanted to see how low the price would go. I was in a social psychology experiment mode. He came back with the price ‘down’ to my target price (the dealer fee was still high, even if I was really interested in the car). I said I’d have to talk with my wife before I committed to anything. They were even trying to get me to make a “fully-refundable” deposit (again, more committal) on the car to “lock in the price so we don’t sell the car tomorrow.” Another great part of this process was how the salesman was always on ‘my side.’ As if he’s not making a commission on this sale! I could see him sweat as I ‘talked’ the price down. OK, that was a bit of literary license – I didn’t see him sweat – but I knew he was looking at a fading commission (unless his boss was going to give him a big commission for actually selling this car). Frank kept stating that he was on my side, “This couple who wants to buy the car doesn’t even have any kids so I’d rather sell it to you since you’ll get better use out of it. You actually need it with three kids. I’d rather sell it to you even though this other couple is willing to pay a couple thousand dollars more than you are for the car.” Wait, what?! He has an opportunity to sell that car for $2000 more and he wants to sell it to me instead? Maybe he really did want to but even my optimistic self was cynical about his statement in light of the rest of the night.

Also, somehow the “wife of this couple [had] already looked at the car” even though they live a couple hours away and the car had “just arrived 24 hours ago.” Maybe he honestly didn’t know when they got the car on the lot but that was a bit too much of “scarce commodity” for me. He was so eager to sell me the car that his stories stopped matching up. Frank stretched the truth one too many times. I saw that he wasn’t going to go down in price any more so I ended my informal experiment. I made my exit and walked away saying that I’d talk to my wife. I did, but mainly to say that we didn’t want that particular car. As I was walking away, Frank knew he had lost me. He asked a couple times, “Was I too pushy?” He realized that he hadn’t been in control of the situation; he hadn’t read me correctly. And yes, at least to me, he was too pushy (but that is just my personal preference. I know he was not particularly pushy as far as car salesmen go).

I went home and searched for the car online. It came up (same dealership) with an online price $200 less than the lowest deal he “cut me”. Most dealerships have separate online salespeople so the general on-lot salespeople are not usually aware of the online price (it’s usually lower than what is offered in person) but I still think it is funny how his best deal for me was higher than the online price. That stems from me telling him my limit in the first place (again, I did that on purpose). I further discovered that the car had been on the lot for about 5 weeks instead of only 24 hours.

I hope I don’t sound like I was being manipulative. I honestly was interested in the car if it was a good enough price (okay, so maybe a toss-a-coin-in-a-well-and-have-a-bag-of-gold-fall-at-your-feet kind of price). It never even came close to what I would be willing to pay for it. Besides, had it come down to it I would have demanded reductions because of the non-power power door as well as other issues. So much for their “thorough inspection” that according to Frank was worth paying upwards of a couple thousand dollars more for a car from them than I could elsewhere.

I laughed much of the way home. This was not laughter aimed at Frank as much as the fact that the whole process was just ridiculous. There’s a reason I do not like dealing with many car salespeople. I know most are good people but on the job they are salesmen; it is their job to sell you a car, even if it sometimes means burnishing the truth a little or a lot. That’s one reason I am not a salesman, I don’t think people should pay more than something is worth.

I share this experience to help people be more aware of common sales techniques. Buying a car is a big decision and is daunting for most people. Remember that you are in control. Watch out for the foot in the door (that doesn’t mean you don’t let them do it, just recognize what they are doing and be willing to walk away). Also, be more alert when the salesperson is doing something as a favor to you. Maybe he or she is but remain skeptical. Actions like that (unless you personally know the salesperson) should raise some red flags. Also watch out for the pressure situations of ’scarcity’; yes, the car really might be sold tomorrow but if you aren’t completely comfortable just walk away. Find a salesperson (at another dealership if possible) who doesn’t pressure you. I’ve met some very nice and good car salespeople who sell cars without resorting to pressure. Also, if the stories of the salesperson start contradicting each other, walk away. Also, don’t give out your price target because they will almost always meet and surpass that target. If you say you can spend $16,000, many dealers will suddenly have $13,000 and $14,000 cars for sale for $16,000. You can give soft estimates of what you are willing to spend but if anything, say you are willing to spend less than you actually are. Again, as the consumer you are always in control (except in emergencies and hopefully then people are not there to take advantage of you) if you do not give up that control. Lastly, sales are not always good deals. Always do your research ahead of time for major purchases like a car.

I’m going to go back online and search more. I’d rather buy a car on eBay than deal with another car salesperson in person. The whole experience was interesting though. There were other sales techniques Frank used but I didn’t go into them. I’m sure I even missed a few. I won’t go into the psychology of sales (meaning explaining how to be a good salesperson), it’s not my expertise, but there are ways of being a great salesperson without pressuring or resorting to dishonesty.

In Memory of H.M. – Live Video

December 3rd, 2009 Jared Tanner No comments

The Brain Observatory – In Memory of H.M..

Click on the above link to watch H.M.’s brain being sliced into histological sections at the University of California – San Diego. The cutting resumes today (Thursday, December 3, 2009) at 11 AM EST. The researchers expect to cover the medial temporal lobes (including what is left of H.M.’s hippocampi). This is a historical event involving the brain of the most studied person in psychology and neuroscience. Who is H.M.? Click here to read my short post about him.

Categories: brain, hippocampus Tags: ,

Are Liberals Smarter Than Conservatives?

October 22nd, 2009 Jared Tanner No comments

Are Liberals Smarter Than Conservatives? — The American, A Magazine of Ideas.

As someone interested in intelligence and politics this article is very interesting. It is written from a conservative viewpoint but it quite balanced (there are some mild jabs at the “liberal elite” though).

“Who are smarter, liberals or conservatives? This is the kind of question that could spark fierce and endless debates between political opponents, but what if we could know, scientifically, that one side has the edge in brainpower? Should that change how we think about political issues?”

Click on the link above to read the rest of the article. Any thoughts about the article? Does IQ really matter? Are conservatives “dumber” than liberals or vice versa? Is it even useful to compare intelligence across the aisle, so to speak?

Writing Memories In the Brains of Flies

October 17th, 2009 Jared Tanner No comments

Source for the following post: BBC NEWS | Science & Environment | Bad memories written with lasers

The brains of flies are far simpler than the brains of humans. Previously, researchers had discovered that only 12 neurons were involved in the formation of associative memories in flies. This most recent study builds on this knowledge. If these 12 neurons are involved in forming memories, could researchers trigger these neurons and create memories?

According to a recently published paper in Cell, the answer is “Yes.” Using genetically-modified flies with adenosine-5′-triphosphate (ATP) activated neurons (the ATP is triggered by lasers), the researchers were able to affect the flies such that “the flies associated the smell with a bad experience, so the laser flash gave the fly a memory of a bad experience that it never actually had.”

Here’s a link to the journal article (requires a subscription).

Here’s the abstract:

“Dopaminergic neurons are thought to drive learning by signaling changes in the expectations of salient events, such as rewards or punishments. Olfactory conditioning in Drosophila requires direct dopamine action on intrinsic mushroom body neurons, the likely storage sites of olfactory memories. Neither the cellular sources of the conditioning dopamine nor its precise postsynaptic targets are known. By optically controlling genetically circumscribed subsets of dopaminergic neurons in the behaving fly, we have mapped the origin of aversive reinforcement signals to the PPL1 cluster of 12 dopaminergic cells. PPL1 projections target restricted domains in the vertical lobes and heel of the mushroom body. Artificially evoked activity in a small number of identifiable cells thus suffices for programming behaviorally meaningful memories. The delineation of core reinforcement circuitry is an essential first step in dissecting the neural mechanisms that compute and represent valuations, store associations, and guide actions.”

You can also listen to an interview with one of the researchers on this episode of NPR’s Science Friday.

As we learn more about how memories are created we might be able to understand and fix problems when memories fail.

Categories: memory, neuroscience Tags:

Prevalence of Psychologists in Argentina

October 16th, 2009 Jared Tanner No comments

A 2008 study found that Argentina has 145 psychologists per 100,000 citizens. That is the highest rate in the world. The Wall Street Journal reports the following numbers (from 2005 – the number of psychologists in Argentina has increased since that time):

“Per Capita: Argentina topped a world ranking of psychologists per capita compiled by the World Health Organization in 2005:

Psychologists per 100,000 inhabitants

Argentina: 121.2
Denmark: 85
Finland: 79
Switzerland: 76
Norway: 68
Germany: 51.5
Canada: 35
Brazil: 31.8
USA: 31.1
Ecuador: 29.1

Also: In 2008, Argentina had 145 psychologists per 100,000 inhabitants; the capital, Buenos Aires, 789, according to a report by Modesto Alonso and Paula Gago. A 2009 national survey conducted by TNS Argentina found that 32% of respondents had at some time made a psychological consultation. That was an increase from 2006, when 26% said they had.”

Does anyone know why Argentina has much higher rates of psychologists than other countries? Buenos Aires particularly has a very high concentration of psychologists. What is further interesting is that many of the psychologists – at least inferred from the article – have a psychodynamic background.

So why does Argentina have a high concentration of psychologists? When looking at the list of countries with rates higher than the United States there are a number of possible explanations. One is that psychology is valued more in those countries than it is in the United States. Maybe the people are more trusting of psychologists and open to psychotherapy. Another possible explanation is that people in those countries are more depressed or anxious or have other psychopathology. They also could have fewer other resources to which they can turn for support (e.g., family or clergy or friends). Another possible answer is that there is something about the countries that make psychologists more prevalent. It could be political (maybe more turmoil or less stable governments), criminal (higher rates of crime), or some other psychosocial factor. It’s possible that higher rates of psychologists is related to prevalence of socialistic philosophy. Maybe psychologists in those countries are paid better than they are in countries with lower numbers per capita of psychologists. There could be any number of reasons why there is a higher prevalence of psychologists in Argentina (and other countries for that matter). Any additional thoughts?

Post-operative Cognitive Dysfunction

September 29th, 2009 Jared Tanner 7 comments

Visit this link to my article on Brain Blogger to read a brief description of post-operative cognitive dysfunction (POCD). Here is a selection of what I wrote.

In the mid 1950s, Dr. Bedford reported on a number of older adults who exhibited cognitive problems (memory or planning or being able to sustain attention) following surgery where anesthesia was used. This effect is now called postoperative cognitive dysfunction (or decline; POCD). POCD typically lasts for a few months to a year with a small minority of patients exhibiting permanent decline. Studies about it were few at first, with most focusing on cognition following cardiac surgery. Over time and especially more recently, there has been an increase in research of POCD following non-cardiac surgeries (e.g., abdominal or orthopedic) as well as continued interest in POCD following cardiac surgery.

Click here to continue reading.

Categories: cognition, memory Tags: , , ,

The Relationship Between Executive Function and Processing Speed

July 15th, 2009 Jared Tanner No comments

Understanding the relationship between brain (specifically subcortical structures) and cognitive processes is a field still in its infancy. The rise of structural and functional neuroimaging that started in the 1970s and really began to mature in the 1990s (with even greater changes and advancements being made today), led to the ability to measure the structure and function of various brain regions in vivo. This was and is important for neuropsychologists because it allowed them to more accurately assess the relationship between the brain and cognitive and behavioral functions.

Processing speed is a basic cognitive or brain processes that subserves many other higher-order cognitive domains. Among those higher domains is executive functioning, a somewhat broad construct that involves the organization of behaviors and behavior responses, selective attention of pertinent information and suppression of unnecessary information, and maintenance and shifting of cognitive sets. Thus, executive functioning is dependent on processing speed but processing speed is not dependent on executive functioning. If executive functioning is a car, processing speed is the engine. Having a faster or more powerful engine means that the car can go faster. More efficient engines allow the car to function at a higher level of efficiency. Thus, while processing speed and executive functions are distinct, they are related with processing speed as one of the basic cognitive processes driving executive functions.

As an example of the interaction between executive functions and processing speed in clinical applications we can look at the Stroop Color-Word task. A person who is not only able to read the words or name the colors quickly but also able to inhibit the undesired but automatic process (namely, word reading on the incongruent color-word task) will receive a higher score on the Stroop task. This would, in combination with other executive function tests, be evidence for intact or even good executive functioning.

Even on non-speeded executive tasks those with fast processing speed can benefit because they can sort through information more quickly and hopefully, efficiently – speed and efficiency are related but not exactly the same. However, not all tests of executive function rely on processing speed. A person, for example, could be slow on the Wisconsin Card Sort Test, yet not exhibit any “executive dysfunction” in that they could complete all the categories and not have an abnormal number of perseverative errors. This simply demonstrates that “executive functions” are diverse and varied.

As a basic process that is dependent on basic neuronal function and glial support, any sort of focal or diffuse injury to the brain can affect processing speed. An example of this is traumatic brain injury, which frequently results in diffuse axonal injury; this diffuse injury negatively affects cognitive processing speed. Any time the white matter is focally or grossly disrupted, processing speed is in danger of disruption itself. This disruption of white matter could be anything from axonal damage, loss of oligodendroglia (which form the myelin), or even low levels of neurotransmitters.

White matter disruption also occurs in multiple sclerosis where diffuse lesions are apparent in the white matter. This disruption also occurs more often in people with heightened vascular risk factors, such as hypertension, diabetes, and cardiovascular disease. People who have these vascular risk factors and subsequent damage to their white matter (this damage or disruption is frequently termed leukoaraiosis) have reduced processing speed and attention (Viana-Baptista et al., 2008). Lesions to subcortical structures, such as the caudate, also result in reduced processing speed (Benke et al., 2003) in addition to executive dysfunction.

In subcortical disease processes such as Huntington’s disease, which usually starts with atrophy of the caudate nuclei, or Parkinson’s disease, which starts with a loss of the majority of dopaminergic cells in the substantia nigra, processing speed is consistently affected. Some common symptoms of Parkinson’s disease are freezing and a shuffling gait; even though these symptoms are motoric, they can be indicative of the global cognitive slowing that also occurs. However, it seems that processing speed is heavily dependent on the integrity of white matter.

Because of the diffusivity of processing speed, I am not aware of any areas of the brain shown to be necessary for processing speed, outside of global white matter. As I mentioned above, damage to the caudate has been shown to affect processing speed but damage to almost any area of the brain, especially if the white matter is disrupted results in slowed processing speed. Neuropsychologists often talk about a patient who has executive dysfunction, slowed speed of processing, as well as some other cognitive deficits as exhibiting signs of a frontal-subcortical disruption – a frontal-subcortical profile. So far, no one has localized processing speed to a single area – many brain structures or areas affect it.

At this point, processing speed and executive functions cannot be “mapped” to separate basal ganglia structures or loops. Of the three classically recognized cortico-striato-thalamo-cortical loops involved in cognitive and emotional processes rather than basic motor processes, which were first introduced by Alexander, Delong, and Strick (1986), the dorsolateral prefrontal cortex circuit appears to be most correlated with processing speed (Mega & Cummings, 1994). This is also the circuit most strongly linked with executive functioning. It appears that rather than utilizing different circuits processing speed and executive functions utilize the same circuits; however, processing speed is much more globalized.

References

Alexander, G. E., DeLong, M. R., & Strick, P. L. (1986). Parallel organization of functionally segregated circuits linking basal ganglia and cortex. Annual Review of Neuroscience, 9, 357-381.

Benke, T., Delazer, M., Bartha, L., Auer, A. (2003). Basal ganglia lesions and the theory of fronto-subcortical loops: Neuropsychological findings in two patients with left caudate lesions. Neurocase, 9, 70-85.

Mega, M. S., & Cummings, J. L. (1994). Frontal-subcortical circuits and neuropsychiatric disorders. The Journal of Neuropsychiatry and Clinical Neurosciences, 6, 358-370.

Viana-Baptista M, Bugalho P, Jordão C, Ferreira N, Ferreira A, Forjaz Secca M, Esperança-Pina JA, Ferro JM. (2008). Cognitive function correlates with frontal white matter apparent diffusion coefficients in patients with leukoaraiosis. Journal of Neurology, 255, 360-366.

What is Executive Function?

July 10th, 2009 Jared Tanner 4 comments

Executive function is a term that describes a wide range of cognitive behaviors and processes. It is broad enough of a term that some people simply describe it as, “what the frontal lobes do.” When asked what exactly the frontal lobes do do, some revert to the circular definition of “executive functions.” However, executive functions are distinct from – but related to – what the frontal lobes do. The frontal lobes are involved in motor functions (e.g., pre-motor and primary motor areas), eye movement (e.g., frontal eye fields), memory (e.g., acetylcholine-producing portions of the basal forebrain), and language (BA 44,45 or Broca’s area). In addition, some executive functions incorporate areas of the brain outside the frontal lobes – the parietal lobes or basal ganglia, for example. Like many cognitive domains, executive functions are part of a distributed network of brain structures and regions.

Most neuropsychologists however, would define (or at least accept the following definition of) executive function similar to this: Executive function is the ability to selectively attend to, work with, and plan for specific information. This means that executive function is deciding what information, cognitions, or stimuli are relevant, holding and working with that information, and then planning what to do with it. As such, executive function is largely the roles of planning and organization. It is also the ability to recognize and learn patterns (i.e., cognitive sets) but also have the cognitive flexibility to respond to set changes and make a shift in set. Executive function also involves being able to select the appropriate response or behavior while at the same time inhibiting inappropriate responses or behaviors.

Executive functions have been compared to the conductor of an orchestra who, in order to make sense of the disparate instruments, sounds, and parts, must coordinate the members and lead the efforts of all the components of the orchestra. Executive functions also have been compared to chief executive officers of companies. These comparisons demonstrate that executive functions are arguably the most complex and highest of all cognitive functions. However, just like most other cognitive functions, executive functions are comprised of relatively simple processes (e.g., attention and processing speed) – it is just the unique combination of these more basic processes that makes executive functions so powerful.

One potential problem with executive function as a cognitive domain is that it is large and loose. Many tests have been developed, or at least used, to assess executive function (e.g., Wisconsin Cart Sort Test, Stroop Color-Word Task, clock drawing, and so forth). Even though all such tests are used as measures of executive functioning, scores on them do not always correlate highly with each other. They do not always cluster together when subjected to principal components analysis or even structural equations modeling. This means that even though neuropsychologists have many purported tests of executive function, they all seem to measure different aspects of executive function. This might partially result from executive functioning tests being differentially affected by basic cognitive processes such as processing speed.

Even though, as previously mentioned, I do not believe executive functions and frontal lobe functions are synonymous terms, are we able to localize executive functions to the frontal lobes? Largely we can. The most evidence from neuroimaging studies and neurological injuries demonstrate that the prefrontal cortex – the area of the brain that is phylogenetically youngest and most advanced and as such, proportionately larger in humans than any animal – is necessary (but not necessarily sufficient) for executive functioning. When this area is disrupted in humans, they exhibit poor decision-making skills, including poor planning and poor maintenance or self-regulation of behavior. One area of the prefrontal cortex particularly involved in executive functions is the dorsolateral prefrontal cortex (area 46) – although both the orbitofrontal and anterior cingulate are involved in aspects of executive functions.

In 1986 Alexander, Delong, and Strick published their seminal work on five parallel and closed cortico-striato-thalamo-cortical loops. These frontal-subcortical circuits were hypothesized to be involved in a range of behaviors and cognitions based on the varying cortical connections of the loops. Previously, many researchers did not well-understand the role that the basal ganglia played in any sort of “higher” function; in fact, most viewed the basal ganglia as involved mainly in motor behaviors. Alexander, Delong, and Strick’s article set off a flurry of research into the functions of these frontal-subcortical circuits, which have been verified as existent in humans (Middleton & Strick, 2000). Over time different theories have modified these circuits, including that they are composed of direct, indirect, and hyperdirect pathways, which all function at different speeds or timings to allow the basal ganglia to regulate behavior. Mink (1996) proposed that actions (e.g., producing a specific word) are regulated by the direct and indirect pathways, which serve as large components of our ability to select and inhibit correct and incorrect responses, respectively. It is as if each individual fronto-cortical loop allows us to properly attend to the correct behavior or response and inhibit all other behaviors or responses, much like the DLPFC and orbitofrontal cortex and their associated loops are involved in the selection and inhibition of behavior, both major aspects of executive function.

Just as damage to the dorsolateral prefrontal cortex (DLPFC) produces deficits in executive function, damage to any part of the DLPFC loop also results in executive dysfunction. Benke, Delazer, Bartha, and Auer (2003) presented two clinical cases of patients with left caudate lesions (the lesions also affected part of the anterior limb of the internal capsule as well as portions of the putamen and pallidum; however, the infarcts affected the caudate the most). Among other deficits, both patients had executive function impairments, including problem-solving deficits, many perseverative errors, and set-shifting problems. Even though the patients had no direct DLPFC damage, they exhibited similar deficits to patients with DLPFC lesions. These executive deficits persisted over time.

As a cognitive domain, and even as broad as it might be, executive functioning has ecological validity. Price and colleagues (2008) found that executive dysfunction was related to greater difficulty performing IADLs. Specifically, patients with executive dysfunction had more difficulty performing IADLs than patients with memory deficits did. Thus, how quickly, flexibly, and accurately people can organize, solve, plan, or attend to specific neuropsychological tasks seems to correlate with their accomplishment of everyday tasks of life, such as finances, driving, and shopping.

References

Alexander, G. E., DeLong, M. R., & Strick, P. L. (1986). Parallel organization of functionally segregated circuits linking basal ganglia and cortex. Annual Review of Neuroscience, 9, 357-381.

Benke, T., Delazer, M., Bartha, L., Auer, A. (2003). Basal ganglia lesions and the theory of fronto-subcortical loops: Neuropsychological findings in two patients with left caudate lesions. Neurocase, 9, 70-85.

Middleton FA, & Strick PL. (2001). Basal ganglia output and cognition: evidence from anatomical, behavioral, and clinical studies. Brain Cogn., 42, 183-200.

Mink, J. W. (1996). The basal ganglia: Focused selection and inhibition of competing motor programs. Prog Neurobiol, 50, 381-425.

Price, C.C., Garvan, C., and Monk, T. (2008). Type and severity of cognitive impairment in older adults after non-cardiac surgery. Anesthesiology, 108, 8-17.

Video of my brain

April 14th, 2009 Jared Tanner No comments

I posted a video of my brain on YouTube just to show the quality of MRI scans we have now (and the fun things we can do with post-processing). The scans were done on a 3T Philips Achieva MR scanner. We acquired 2 T1 scans of my brain (160 1mm slices – 1 mm cubed voxel size) then post-processed the DICOMs using FreeSurfer. The skull-stripped output files (in NIFTI format) were then rendered in 3D in OsiriX. I created a fly-through movie of the brain and exported it as an MP4 movie. If you have any questions about the process, feel free to ask.

Categories: brain, mri, video Tags: ,

Mad Cow And Alzheimer’s Have Surprising Link : NPR

February 26th, 2009 Jared Tanner No comments

Mad Cow And Alzheimer’s Have Surprising Link : NPR. If this research showing a link between prion proteins and the deleterious effects of beta-amyloid plaques in rat brains holds true in humans, it has huge implications for finding a cure for Alzheimer’s disease. That would be as big as the polio vaccine or eradicating small pox. This is some research that is worth watching closely.