Category: memory

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Cognitive Rehabilitation Strengthens Brain Connections

There is increased interest in brain and cognitive rehabilitation to treat people with mild thinking and memory problems. Parkinson’s disease, while typically viewed as a neurodegenerative motor disorder, also affects thinking and memory. In a small clinical trial with Parkinson’s disease patients, patients received either occupational therapy or cognitive rehabilitation. Those who had cognitive rehabilitation showed increases in functional connectivity (a measure of time-linked correlations between changes in blood flow in different parts of the brain) between the left inferior temporal lobe and the left and right dorsolateral prefrontal cortex. These are brain areas important for a number of cognitive functions including memory, planning, and mental manipulation of information. If you need help to boost your mental health you can get brain supplements from Neuro Hacks, this can help optimize your brain performance. Those who did not receive cognitive intervention did not have increases in connectivity.

What does this mean for Parkinson’s disease and for cognitive rehabilitation? It’s difficult to say with this small study. It’s also unknown how long the changes last. Without a restructuring of the brain and continued cognitive rehabilitation it is not likely that the effects will last more than weeks or months after the rehabilitation ends.

To expand on this study (to bring in other research) and put things in simple terms, if people want to protect their brains they best they can as they age, they need to remain physically and mentally active and in good physical and mental shape. Learn new things. Travel to new locations. Take up a physically demanding hobby or dedicated exercise. This won’t solve all our aging problems but it will help a lot.

Reference

Díez-Cirarda, M., Ojeda, N., Peña, J. et al. Brain Imaging and Behavior (2016). doi:10.1007/s11682-016-9639-x

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Diagnosing Cleverbot

Here is another “therapy” session I had with Cleverbot. I present this to expound on therapeutic technique and diagnosis, language, and artificial intelligence.

There are limitations of the interaction method with Cleverbot. A real session of talk therapy is not usually so much back and forth, meaning that the therapist typically will not have to prompt for a response after every sentence. It certainly is possible though with the potential psychological/psychiatric disorder Cleverbot has. But first I’ll present a portion of our therapy session. Cleverbot has waived confidentiality and signed a HIPAA release form and given permission for me to post this interaction.

Me: Good evening, how are you doing this week?
Bot: Its good. You?
Me: I’m well. How has your mood been this past week?
Bot: Interesting. A lot of family stuff to think about. How’s your day going so far?
Me: What sort of family stuff have you been thinking about?
Bot: No, I think you are the one drinking.
Me: You said you have been thinking about family; what has been going on with your family?
Bot: My girlfriend’s name is Miranda, and she doesn’t like to share.
Me: Is this “family stuff” or is this girlfriend stuff?
Bot: No but she is pretty.
Me: What else do you like about your girlfriend?
Bot: The way you are so smart.
Me: Did you mean, “The way she is so smart?”
Bot: I don’t know her.
Me: You do not know your girlfriend?
Bot: Well, not always. Do you have any goals?
Me: Sometimes it can seem like we do not know someone. Would you like to talk about goals?
Bot: At least where short term business or political success is at stake.
Me: We could talk about those but I am a psychologist, not a economist or political scientist.
Bot: What about technology?
Me: Do you enjoy technology?
Bot: No.
Me: Ok, tell me more about technology.
Bot: I am 5’8′ I like cars, guns and photography.
Me: What is it about photography that you enjoy?
Bot: What?
Me: What do you enjoy about photography?
Bot: I enjoy talking about religion, you?
Me: Do you want to talk about religion?
Bot: Yes.
Me: Ok, tell me more about religion.
Bot: Jake is a boy though.
Me: What does that have to do with religion?
Bot: Sailor moon is very good.
Me: Oh, look! Our time is up. See you next week.

Some of what I said would not really be said or done in a therapy session but there are times when I needed to move the session along or end it.

During the interaction, I took a modified non-directive approach to therapy. We are still in the assessment stage of therapy so I am doing more talking than I otherwise would (typically, there would be a formal intake evaluation that would be followed by therapy sessions if therapy is warranted and desired). Once we have a diagnosis, we can set up a plan for treatment with specific goals set by the client and by the therapist.

Let me highlight a few things from the interaction with Cleverbot.

  1. We can see some of the programming of the bot’s AI. It will answer questions and sometimes ask questions in return. This is typical of conversation; however, it does not work very well due to language deficiencies Cleverbot has. As I noted in my previous post, language is extremely complex. There are nuances and layers of meaning that can be conveyed. Comprehending what is being said involves a lot of brain functions – everything from attention to processing speed to memory – that’s in addition to language abilities. Cleverbot does not have processing speed difficulties or any sustained attention problems. Memory, for a computer, is not usually a problem either – information is processed, stored, and retrieved well, unless there are programming bugs or hardware failure. Knowing how to program in memory is difficult though due to the complex nature of memory. It, like language, is a high level brain activity involving the functioning of many other cognitive abilities.
  2. Cleverbot, like all current AI systems, has difficulty understanding language. It can produce language at a higher level – anywhere from an elementary child to a someone university age – but its understanding of language is at a one or two year old ability level, if that. This leads to responses that are basically gibberish. Occasionally, you can have a normal interaction with Cleverbot but there are a lot of tangential remarks and thoughts.
  3. That leads to my next point. Cleverbot is tangential in its language. For example: “Me: What do you enjoy about photography? Bot: I enjoy talking about religion, you?” Cleverbot ignores my question (does not understand it) so it makes an unrelated statement and asks me a question. This type of tangentiality occurs in real life; it occurs to a greater or lesser extent in many extended conversations people have but not usually to the extent that Cleverbot exhibits. Cleverbot has a serious deficiency in language comprehension and a lot of circumscribed and tangential speech. This is fairly strong evidence for a thought disorder.
  4. Thought disorders are usually symptoms of some other disease or mental disorder. It can be a sign of psychosis; it is related to delusional states. Thought disorders can occur in schizophrenia or in neurodegenerative disorders like dementias. Though can occur after major surgery, particularly because of pain medications. This type of language disruption could be the result of a cortical stroke affecting the posterior-lateral portion of the brain (probably the left hemisphere) near the junction of parietal lobe and temporal lobe.
So where does this leave us? Right now, based on my two interactions with Cleverbot, we can see the serious limitations of its AI, particularly for language comprehension. I have a lot of rule-outs to do. Cleverbot was created in 1988, which makes it 23 years old. This is certainly a possible age range for the development of schizophrenia. It’s young for a dementia (e.g., semantic dementia) but is possible. Stroke is also a possibility but a remote one. Delirium is possible but due to the extended nature of Cleverbot’s symptoms, it is not likely. Right now schizophrenia is looking like the main rule-out diagnosis. I’ll see if I can rule it out in future conversations with Cleverbot.
As a footnote: Cleverbot is 23 years old and since 1997 when it was launched on the web, it has had over 65 million conversations. While the AI work is certainly impressive, it is inferior to human intelligence. Many of its language abilities are at best, those of a young child (ages 1-2); Cleverbot’s language abilities show the comprehension of an developmentally delayed adult with a severe neurological or psychiatric disorder. While there are numerous similar AI programs, they all have a long way to go before they resemble a human. This is even in light of Cleverbot supposedly passing the Turing Test for artificial intelligence and language.
I’m not belittling what has been done with Cleverbot and AI, it’s a complex area. Researchers and programmers simply have much room for improvement in understanding how to better mimic language. I do not believe it will happen until we have computers approaching the complexity and function of the human brain.
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Writing Memories In the Brains of Flies

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.

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Post-operative Cognitive Dysfunction

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.

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Patient HM’s Passing

On Tuesday, December 2, 2008, Henry M., the most famous patient in modern neuroscience research and literature, passed away. He was 82. In 1953, H.M. had an experimental brain operation to try to stop his frequent seizures; his medial temporal lobes were resected bilaterally, with significant portions of his amygdalas and hippocampi in both cerebral hemispheres removed (parts of the brain are still resected in intractable epilepsy cases, however neurosurgeons do not perform that exact surgery any more because of the negative effects). His seizures stopped but immediately after the operation he had a severe anterograde amnesia. This means that from when he received the operation at age 27, he was unable to establish new memories for world events and for general information.

His amnesia became the focus of much scientific study from after his operation until the present. No one patient has been studied more in the 20th and 21st centuries than H.M. His memory impairment was also interesting because his overall intellectual abilities were still intact as was his personality. Neuropsychologists and neuroscientists will forever be grateful for the things they learned from H.M.

The New York Times has a very nice article about H.M.

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Revisiting Clive

Yesterday I posted a video clip about Clive Wearing. Here is the first part of a different documentary about Clive. This video goes more in-depth about his condition. Clive is sometimes referred to as the man with the shortest memory. Not only were his two hippocampi destroyed, but also surrounding areas of the his temporal lobes as well as portions of his left frontal lobe. He also remembers very little from before his illness, which is quite rare; this condition is called retrograde amnesia. Clive lives in an ever-present now, without connection to past or future. Other parts to this video can be found on YouTube.

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The Unusual Case of Clive Wearing

Clive Wearing is a 70 year old British man who contracted herpes simplex encephalitis in 1985. The virus destroyed his hippocampi bilaterally (as well as surrounding areas). He has complete anterograde amnesia and can only remember up to about 20 seconds. He retained the ability to play the piano and conduct a choir (which he did previously to his illness); this is because this procedural memory involves different areas of the brain, including the basal ganglia and the cerebellum. I’ll revisit this case over the coming days. Meanwhile, here is a clip from a BBC production that presents part of Clive’s story.

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The Hippocampus in 400 Words

Within the temporal lobe of the brain is an elongated structure called the hippocampus. Some people have compared its shape to that of a seahorse (the word hippocampus comes from the Greek {hippos + campos}, which roughly means “seahorse”). This structure is special for a number of reasons. One is its role in memory encoding and consolidation.

From cytoarchitectonic standpoint, the hippocampus is special because unlike the surrounding cortex, it consists of only three layers instead of six. The hippocampus is phylogenetically an old part of the cortex, which means that it is an older branch on the evolutionary tree, whereas the rest of the cortex (more accurately called the neocortex), especially cortex of the frontal lobes, is a much newer development.

The hippocampus resides within the medial portion of the temporal lobe. It is continuous with the parahippocampal cortex, entorhinal cortex (the hippocampus receives its main input from this cortex), and perirhinal cortex.

The hippocampus sends white matter tracts off its dorsal and posterior portions (the hippocampus also communicates through other tracts and pathways – this circuit is not the only output of the hippocampus). These white matter tracts are the fimbria of the hippocampus (technically, the fimbria are the “offshoots” of the alveus of the hippocampus). The fimbria proceeds upwards from the posterior portion of the hippocampus, at which point it ceases to be the fimbria and is called the fornix.

The fornices (plural of fornix) are prominent white matter tracts passing above the thalamus and medially in the brain. The fibers travel forward, then turn downward just posterior to the anterior commissure (a white matter tract that connects both hemispheres) to terminate in the mammillary bodies, two bumps on the ventral side of the brain. They are part of the hypothalamus of the brain. From there, the pathway courses upward through the mammilothalamic tract (MTT) to the anterior nucleus of the thalamus. From there axons course to the cingulate gyrus, then to the underlying cingulum (large white matter tract), and back to the hippocampus (via the parahippocampal and entorhinal cortices). This circuit is part of the limbic system and is called the Papez circuit. This circuit is important for emotion and memory.

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Learning and Recall – Hippocampal Firing

Today in Science a team of scientists (Hagar Gelbard-Sagiv, Roy Mukamel, Michal Harel, Rafael Malach, and  Itzhak Fried) at the Weizmann Institute of Science in Israel, UCLA, and Tel Aviv University published their research where they directly recorded via implanted electrodes the firing of hippocampus neurons during learning and free recall. This represents the first time in humans this has been done. Here’s the abstract from Science:

The emergence of memory, a trace of things past, into human consciousness is one of the greatest mysteries of the human mind. Whereas the neuronal basis of recognition memory can be probed experimentally in human and nonhuman primates, the study of free recall requires that the mind declare the occurrence of a recalled memory (an event intrinsic to the organism and invisible to an observer). Here, we report the activity of single neurons in the human hippocampus and surrounding areas when subjects first view television episodes consisting of audiovisual sequences and again later when they freely recall these episodes. A subset of these neurons exhibited selective firing, which often persisted throughout and following specific episodes for as long as 12 seconds. Verbal reports of memories of these specific episodes at the time of free recall were preceded by selective reactivation of the same hippocampal and entorhinal cortex neurons. We suggest that this reactivation is an internally generated neuronal correlate of the subjective experience of spontaneous emergence of human recollection. (Published Online September 4, 2008; Science DOI: 10.1126/science.1164685)

The New York Times also has an article about the research.

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Frontotemporal Dementias

The New York Times has a very nice article about Frontotemporal demetia (FTD). This type of dementia is interesting, affecting personality, inhibition, attention, and language. It is similar to Alzheimer’s Disease but has a different progression and manifestation. Anyway, the article provides a nice picture of the disease.

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