Thursday, May 24, 2007

TMS causes nurogenesis and LTP in the mice brain!

Transcranial Magnetic Stimulation (TMS) has been shown to be effective in treating depression and schizophrenia , but the exact mechanisms were unknown. TMS is nomally utilized for 'knocking off' activity of a brain region near the skull. If this brain area serves an inhibitory function, TMS would lead to more activation in some other connected areas of the brain and vice versa.

As per this blurb from the New Scientist, Battaglia and colleagues found that repeated TMS application to mice hippocampus (dentate gyrus) over a period of 5 days lead to more stem cell neurons there and also lead to strengthening of existing synaptic connection by means of Long Term Potentiation(LTP). It should be noted that hippocampus is one of the prime areas in human brain where neurogenesis happens.

I have blogged earlier regarding the depression-as-low-neurogenesis-in-hippocampus theory and this finding seems to support that theory and provides a mediating mechanism of neurogenesis via which TMS may be leading to alleviation of depression. The researchers also believe that this finding would help in making devices that could lead to alleviation of learning and memory problems like that faced in the Alzheimer's.

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Wednesday, May 23, 2007

Encephalon #23 is online now!

The 23rd edition of Encephalon is now available at Madam Fathom. My favorites include the Muller cell as optical fibers post by the Neurophilosopher.


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Tuesday, May 22, 2007

Theories of Intelligence : Entity Vs Incremental theory

I have blogged previously about Carol Dweck's work on how beliefs about intelligence affect performance outcomes. A new paper from her lab demonstrates how having a fixed or entity like belief of intelligence (talent based) leads to poorer academic achievement as compared to students who have a incremental or malleable concept of intelligence (effort and skill based). I'll let the authors themselves describe the two frameworks:

In this model , students may hold different ‘‘theories’’ about the nature of intelligence. Some believe that intelligence is more of an unchangeable, fixed ‘‘entity’’ (an entity theory). Others think of intelligence as a malleable quality that can be developed (an incremental theory). Research has shown that, even when students on both ends of the continuum show equal intellectual ability, their theories of intelligence shape their responses to academic challenge. For those endorsing more of an entity theory, the belief in a fixed, uncontrollable intelligence 'a ‘‘thing’’ they have a lot or a little of' orients them toward measuring that ability and giving up or withdrawing effort if the verdict seems negative. In contrast, the belief that ability can be developed through their effort orients those endorsing a more incremental theory toward challenging tasks that promote skill acquisition and toward using effort to overcome difficulty.

Relative to entity theorists, incremental theorists have been found (a) to focus more on learning goals (goals aimed at increasing their ability) versus performance goals (goals aimed at documenting their ability; (b) to believe in the utility of effort versus the futility of effort given difficulty or low ability (c) to make low-effort, mastery-oriented versus low-ability, helpless attributions for failure and (d) to display mastery-oriented strategies (effort escalation or strategy change) versus helpless strategies (effort withdrawal or strategy perseveration) in the face of setbacks. Thus, these two ways of thinking about intelligence are associated with two distinct frameworks, or ‘‘meaning systems’’ , that can have important consequences for students who are facing a sustained challenge at a critical point in their lives. It is important to recognize that believing intelligence to be malleable does not imply that everyone has exactly the same potential in every domain, or will learn everything with equal ease. Rather, it means that for any given individual, intellectual ability can always be further developed.

The paper presents two studies. In the first study young children entering 7th grade were measured on their theories of intelligences as well as assessed on different motivational factors. Their performance for a couple of years was monitored and the data was analysed to find the relationships between theory of intelligences and performance outcomes and also to determine the mediating motivational factors . The results are as follows :

The process model suggests multiple mediational pathways. That is, it suggests that

(a) learning goals mediate the relation between incremental theory and positive strategies,
(b) positive strategies mediate the relation between learning goals and increasing grades,
(c) effort beliefs mediate the relation between incremental theory and helpless attributions,
(d) effort beliefs mediate the relation between incremental theory and positive strategies,
(e) helpless attributions mediate the relation between effort beliefs and positive strategies,
(f) positive strategies mediate the relation between effort beliefs and increasing grades, and
(g) positive strategies mediate the relation between helpless attributions and increasing grades.

The second study involved an experimental intervention based approach. Those students who had declining grades were divided in two groups- an experimental one which got interventions that endowed them with a malleable and incremental theory of intelligence and a control group. This study found that grades improved for those in the experimental condition. Overall quite a cool research paradigm which has the tremendous potential to affect education as well as achievement outside of academics.

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Stories we tell ourselves

NYT has a pretty good article on narratives or the life stories that we tell ourselves to make some sense of our lives. Each of us conjures the disparate experiences that we have had into a coherent narrative or life story of who we are, how we have become like that and where we are headed for.

Narratives are on often ignored aspect of psychology an not much research is done on them, though they are very essential for us and are important in that they give us a framework in which we reconstruct our memories or think about the future.

The article mentions the work of Dr McAdams with narratives and having some types of narratives affect future outcomes. I'll just quote from the article:

In analyzing the texts, the researchers found strong correlations between the content of people’s current lives and the stories they tell. Those with mood problems have many good memories, but these scenes are usually tainted by some dark detail. The pride of college graduation is spoiled when a friend makes a cutting remark. The wedding party was wonderful until the best man collapsed from drink. A note of disappointment seems to close each narrative phrase.

By contrast, so-called generative adults — those who score highly on tests measuring civic-mindedness, and who are likely to be energetic and involved — tend to see many of the events in their life in the reverse order, as linked by themes of redemption. They flunked sixth grade but met a wonderful counselor and made honor roll in seventh. They were laid low by divorce, only to meet a wonderful new partner. Often, too, they say they felt singled out from very early in life — protected, even as others nearby suffered.

The article also mentions the work of Dr Adler, that links the psychotherapeutic outcomes with the life stories people tell about themselves.

At some level, talk therapy has always been an exercise in replaying and reinterpreting each person’s unique life story. Yet Mr. Adler found that in fact those former patients who scored highest on measures of well-being — who had recovered, by standard measures — told very similar tales about their experiences.

They described their problem, whether depression or an eating disorder, as coming on suddenly, as if out of nowhere. They characterized their difficulty as if it were an outside enemy, often giving it a name (the black dog, the walk of shame). And eventually they conquered it.

“The story is one of victorious battle: ‘I ended therapy because I could overcome this on my own,’ ” Mr. Adler said. Those in the study who scored lower on measures of psychological well-being were more likely to see their moods and behavior problems as a part of their own character, rather than as a villain to be defeated. To them, therapy was part of a continuing adaptation, not a decisive battle.

Lastly, the article touches upon researches that show that manipulating the retrieval of memories in third person vis-a-vis in the first person leads to better outcomes as oneses oneself as better adjusted after third person recall of significant life events.

Two clear differences emerged. Those who replayed the scene in the third person rated themselves as having changed significantly since high school — much more so than the first-person group did. The third-person perspective allowed people to reflect on the meaning of their social miscues, the authors suggest, and thus to perceive more psychological growth.

The recordings showed that members of the third-person group were much more sociable than the others. “They were more likely to initiate a conversation, after having perceived themselves as more changed,” said Lisa Libby, the lead author and a psychologist at Ohio State University. She added, “We think that feeling you have changed frees you up to behave as if you have; you think, ‘Wow, I’ve really made some progress’ and it gives you some real momentum.”

I would love to hear of more literature in this area.


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Moral Reasoning: two competing processes for intention and outcome identified

In a recent study, by Young, Hauser et al at the Harvard University, the authors tried to experimentally determine whether there is an interaction between intention or belief regarding an action vis-a-vis the actual outcome of the action. For this they used fMRI scans in a 2x2 study involving (negative and neutral) beliefs versus (negative and neutral) outcomes wherein their could be four combination : (competent criminal) intent to harm plus actual harm; (incompetent criminal) intent to harm but no actual harm; (accidental harm) no intent to harm but actual harm and lastly (harmless act) neither intention to harm nor any actual harm. The figure below clarifies this in further detail using an example scenario that was presented to the participants and the participants asked to judge whether the conduct was proper or not and to judge the protagonist's action on a scale of 1..5 regarding whether it was morally permissible or not.

Before I proceed further I'll like to quote from the introduction :

In the common law tradition, criminal conviction depends on both a harmful consequence (actus reus) and the intent to harm (mens rea) . In violation of this foundational legal principle, however, are crimes of attempt. The incompetent criminal, for instance, who believes he has poisoned his victim but has instead administered only a harmless substance, can be convicted in a court of law. This poses a challenge to the philosophy of law: is the basis of criminality an act that causes harm, or an act undertaken with the belief that one will cause harm? We pursue a novel approach to this question based on the burgeoning research into the neurocognitive mechanisms of moral judgment, much of which has emphasized the role of multiple interacting systems . Specifically, we suggest that the apparent philosophical conflict between actus reus and crimes of attempt reflects the operation and integration of distinct mechanisms responsible for the processing of information about consequences and beliefs in the service of moral judgment.

To sum up the papers' findings:

1. They referred to earlier developmental results in children and adults that suggest that children form moral judgments on the basis of outcomes (they will condemn a negative act even if the intention was neutral or even positive) while in adults intention along with outcomes is taken into consideration to form moral judgments.

From a developmental perspective, integrating information about mental states and outcomes presents a particular challenge for young children. When moral scenarios present conflicting information about the outcome of an action and the intention of the actor, young children's moral judgments and justifications are determined by the action's outcome rather than the actor's intention . For example, a person who intends to direct a traveler to the right location but accidentally misdirects him is judged by young children to be "naughtier" than a person who intends to misdirect a passerby but accidentally directs him to the right place . As children mature, they become progressively more likely to make the opposite judgment . Although subsequent research has revealed that young children can use information about intentions to make moral distinctions when consequences are held constant between scenarios , older children have consistently shown greater sensitivity to information about intentions. What develops then is not just "theory of mind," or the ability to represent the mental states of others, but the ability to integrate this information with information about consequences in the context of moral judgment . Developmental evidence thus suggests that mature moral judgments depend crucially on the cognitive processes responsible for representing and integrating information about beliefs and outcomes.

2. They found using fMRI scans that the Right temporo-parietal Junction (RTPJ) was differentially engaged during the above four cases or combinations of intent and outcome. In particular RTPJ showed maximum activation in cases of attempted harm wherein intention to harm was present but the outcome was still positive. The participants condemned the action despite there be no actual harm and this was reflected in higher activations of RTPJ. It is instructive to note the RTPJ is responsible for belief attributions. Thus, this suggests that there are independent moral judgment functions- one dependent on actions and the other on outcomes.

At the broadest level, the results of the current study suggest that moral judgments depend on the cognitive processes mediated by the RTPJ, previously associated with belief attribution, and, to a lesser extent, the PC, LTPJ, and MPFC, which compose a network of brain regions implicated in theory of mind. Specifically, the results reveal significantly above-baseline activation of the RTPJ for all four conditions (intentional harm, attempted harm, unknowing harm, and all-neutral), highlighting the role of belief attribution during moral judgment. Importantly, however, brain regions involved in belief attribution were not recruited indiscriminately across conditions. In particular, we found a selective increase in the response for the case of attempted harm, in which the protagonist believed that he would harm someone but in fact did not. The differential neural response between experimental conditions suggests an unequal contribution of belief attribution to moral judgment depending not only on what the protagonist believes, as might be expected, but also on the consequences of the protagonist's behavior. This result offers a new perspective on the integration of information about beliefs and consequences in moral judgment, the focus of our discussion.

3. They found that accidental harm (unlucky innocents) did not recruit the same brain areas (RTPJ) to that large an extent as attempted harm (incompetent criminal). This was despite the protagonists being judged harsher in accidental harm condition vis-a-vis the neutral case (no bad intention and no actual harm). This suggests that another independent moral judgment function is active and which relies on outcome assessment.

The behavioral data suggest that, across conditions, moral judgment is determined primarily by belief information, consistent with the robust RTPJ response for all four conditions. An interesting asymmetry emerged, however, for cases in which belief and outcome information were in conflict, as in situations of attempted harm and unknowing harm. We found that subjects' moral judgments were determined solely by belief in the case of attempted harm but not unknowing harm. That is, attempted harm (e.g., putting sugar in a friend's coffee believing it to be poison) was judged fully forbidden, just as though the protagonist had successfully produced the negative outcome of the friend's death. By contrast, moral judgment of unknowing harm appeared to depend on both the outcome of the action and on the belief state of the actor. Unknowing harm (e.g., putting poison in a friend's coffee believing it to be sugar) was not judged fully permissible, as compared with the all-neutral condition, in which the protagonist held a neutral belief and produced a neutral outcome.

I find this exciting because I have blogged about this previously in my posts relating to Universal Moral Grammar. In particular I had speculated on there being an Intention predicate, an Action Predicate and a Outcome or Consequence predicate that form this moral grammar. These predicates would each be evaluated separately and independent of each other and their combination would lead to different moral judgments. It is exciting to see that two independent processes related to Intention and Outcome predicate , along with their neural correlates have already been identified. It would only be some time soon that people would also start finding that the nature of the Action undertaken also affects the Moral Judgment to a great extent. The case I can think is that instead of putting poison in the coffee, let us say that the death method was more violent and gory (cutting the throat very slowly while the person is bound). Although the outcome is same, the nature of action would differentially affect the judgments we have towards the protagonists. I would love to see further studies in this direction.

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Friday, May 18, 2007

Mouse Trap's First Blogiversary

Due to some unavoidable business (I have to keep my day job to be able to blog to my heart's pleasure) I have not been regular in writing posts and I apologize to the regular readers of the blog for the same.

This small post is just to commemorate the first blogiversay of The Mouse Trap. I hope yopu have enjoyed the journey so far and would continue patronising this blog.

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