Lines, held by memory.

Lines, held by memory.

Of all the traits associated with the beloved TV series character, Kermit the Frog, he is probably most readily identified by his green color. Surely, this is his most memorable feature and one of his most defining characteristics. So what would happen if Kermit turned blue?  Recently, a Middle Eastern hospital alerted parents to childhood color blindness by featuring this different colored version of Kermit. Presumably, a blue twist of the old familiar green Kermit led to greater attention and better memory of the message. However, is it indeed the case that such novel or odd representations enhance attention and memory?

Memory research is, and has been, dominated by the study of episodic memory — the encoding and retrieval of recently experienced information. Significantly less attention has been given to semantic memory — our existing knowledge networks. Work in my lab lies at an interface between these two approaches: (I.) How does knowledge activated (implicitly or explicitly) during an episode affect memory of this episode? To examine this question, we (II.) consider how our existing knowledge (parts of which become activated during an episode) is organized and stored.

For example:

(I.)          Amnon and Oded

Amnon uses fMRI to study the process of acquiring novel information: While information that was initially novel is shifted into familiarity, associations are formed to embed it within our knowledge base. We investigate the processes under which information that was novel to existing knowledge during its initial presentation, is no longer considered novel by our mental systems, and what factors influence this process.

Oded uses behavioral and fMRI methods to study the influence of familiarity on learning through repetitions. Virtually all previous studies that examined the novelty/familiarity question have used paradigms in which participants process items once, and are then asked to explicitly report their memory of these items. However, people often learn by repeated exposure to associations without any conscious intention to learn. Thus, we learn to associate a person with a style of speech, a place with a smell, a letter combination with a sound, or a certain sub-culture with danger. Our question is: When we incidentally form associations, does existing knowledge about the members of the associations influence this type of learning?   


(II.)         Moran, Yinon, Haim

Moran focuses on trying to find the cognitive differences between opinions and facts - differences that are yet unknown, despite the theoretical distinction between these two forms of knowledge. More generally, we are interested in understanding if, and how, the cognitive system represents facts and opinions differentially, and what role, if any, do individual factors play in this regard.

Yinon's project involves modeling of similarity and conceptualization in the semantic space. We believe that n- dimensional Euclidean space is not suitable for the modeling of similarity and that more complex topological structures should be applied, to account for contextual factors. We argue that reduced dimensionality of representations in the semantic space is a mechanism that underlies abstraction and conceptualization, as well as being a response to stress conditions. These responses to stress, taken to the extreme, may lead to mental illnesses, such as schizophrenia and Alzheimer, which are associated with abstraction disorders. Newly developed brain imaging analysis methods make these hypotheses testable.

Haim aims to shed new light on the cognitive processes underlying moral judgments. Consider the following example: Israeli soldier shot dead a 17-year-old Palestinian who was throwing stones at civilians. Moral judgment can be understood as expressing a belief that can be true or false, e.g. the statement “is morally right to shoot” is false. Yet it can also be understood as expressing a motivational state, akin to a desire, which describes the subject’s disapproval of shooting, e.g. the desirability that a soldier will shoot is low. From the psychological perspective, this study focused on the mental state that people express when they perform a moral judgment.  The main question is "do moral judgments express a cognitive state (as belief) or conative state (as desire)?