Implicit chaining in cotton-top tamarins (Saguinus oedipus) with elements equated for probability of reinforcement

Three experiments examined the implicit learning of sequences under conditions in which the elements comprising a sequence were equated in terms of reinforcement probability. In Experiment 1 cotton-top tamarins (Saguinus oedipus) experienced a five-element sequence displayed serially on a touch screen in which reinforcement probability was equated across elements at .16 per element. Tamarins demonstrated learning of this sequence with higher latencies during a random test as compared to baseline sequence training. In Experiments 2 and 3, manipulations of the procedure used in the first experiment were undertaken to rule out a confound owing to the fact that the elements in Experiment 1 bore different temporal relations to the intertrial interval (ITI), an inhibitory period. The results of Experiments 2 and 3 indicated that the implicit learning observed in Experiment 1 was not due to temporal proximity between some elements and the inhibitory ITI. The results taken together support two conclusion: First that tamarins engaged in sequence learning whether or not there was contingent reinforcement for learning the sequence, and second that this learning was not due to subtle differences in associative strength between the elements of the sequence.     

Images and goals

We propose that mental images are derived from goals. Goals are represented in a complex hierarchy and form a major part of the “working self”. Images reflect the existence of specific goals and also act to maintain goals by facilitating the derivation of beliefs from the content of an image. Images in psychopathology may reflect the operation of dysfunctional goals: goals that are unconstrained and which increase discrepancy (experienced as anxiety) within the goal system. Another feature of the goal system is that it is conservative and avoids change. By this view some aspects of distortions in intrusive images of traumatic experiences might be viewed as a defence against goal change. Conversely generating new images might lead to the formation of new goals. These ideas are applied to the findings of the papers in this special issue of Memory and to several new case studies.     

Personality Factors,Family Structure,and Sex of Drawn Figure on the Draw-A-Person Test

One hundred seventy-four youthful psychiatric inpatients were given the Draw-A-Person Test (DAP) as part of an assessment battery. Sex of person drawn was compared to subject's sex, Achenbach aggression and delinquency scores, and scores on Children's Inventory of Anger and Nowicki-Strickland Locus of Control Scale. The sex of the person drawn was also compared to family composition, specifically whether or not the child came from an intact family with both a male and female parent or role model. Results support drawing of a same-sexed individual as normative, regardless of age or sex. Adolescent girls and young boys were the only groups that differed significantly from this norm. Personality measures and family composition were not significantly related to the tendency to draw same versus opposite sex.     

Remembering and Knowing: Using another’s subjective report to make inferences about memory strength and subjective experience

The Remember–Know paradigm is commonly used to examine experiential states during recognition. In this paradigm, whether a Know response is defined as a high-confidence state of certainty or a low-confidence state based on familiarity varies across researchers, and differences in definitions and instructions have been shown to influence participants’ responding. Using a novel approach, in three internet-based questionnaires participants were placed in the role of ‘memory expert’ and classified others’ justifications of recognition decisions. Results demonstrated that participants reliably differentiated between others’ memory experiences – both in terms of confidence and other inherent differences in the justifications. Furthermore, under certain conditions, manipulations of confidence were found to shift how items were assigned to subjective experience categories (Remember, Know, Familiar, and Guess). Findings are discussed in relation to the relationship between subjective experience and confidence, and the separation of Know and Familiar response categories within the Remember–Know paradigm.     

Are boundary extension and representational momentum related?

Boundary extension (BE) is misremembering more of a particular scene than actually presented. Representational momentum (RM) is misremembering the final position of a moving object as further along its implied trajectory. There is a sense in which both BE and RM are predictions, and the current experiments explore the possibility that these are related phenomena. We showed participants single photographs to measure baseline BE, and then approach sequences and measured BE and RM. We found significant BE and RM, and a significant interaction between baseline BE and BE following an approach sequence, but no interaction with RM. The initial evidence suggests that BE and RM are separate processes, and that BE (the establishing of spatial layout) occurs before RM (the continuation of movement) within a scene.     

Writing and long-term memory: Evidence for a “translation” hypothesis

Two experiments investigated the effects of writing upon memory. In the first experiment an incidental learning procedure was employed: One group of subjects read words silently and wrote visually presented words, and a second group of subjects listened to auditorily presented words and wrote heard words. Recognition of heard words was substantially enhanced by writing, whereas the effect of writing on memory for read words was less powerful. A second experiment employing an intentional learning procedure replicated these findings and demonstrated the robustness of the beneficial consequences of writing on memory for heard words. These findings are conceptualized within a framework that proposes that translations between specialized processing domains that occur at encoding lead to the formation of distinctive memories and, hence, to better retention.