Enhanced perceptual priming for neutral stimuli occurring in a traumatic context: two experimental investigations

Intrusive memories in posttraumatic stress disorder are often triggered by stimuli that are perceptually similar to those present shortly before or during the trauma. The present study aims to examine the possible role of perceptual priming in this phenomenon. It further investigates whether the degree of perceptual priming is associated with dissociation and whether both perceptual priming and intrusive memories can be reduced through elaboration. Two experiments measured perceptual priming for neutral stimuli that immediately preceded a "traumatic" event. Volunteers (N=46, 92) watched a series of "traumatic" and neutral picture stories, and completed a blurred object identification (perceptual priming) memory task, and a recognition memory task. Participants in Experiment 1 were selected to score either high or low on the Trait Dissociation Questionnaire [Murray, Ehlers, & Mayou (2002). Dissociation and posttraumatic stress disorder: Two prospective studies of motor vehicle accident survivors. British Journal of Psychiatry, 180, 363-368]. They also completed a state dissociation measure in the session. Experiment 2 randomly allocated participants to an experimental condition designed to increase elaboration or to a control condition. This experiment also included a measure of intrusive memories. Both experiments found enhanced perceptual priming for the stimuli that immediately preceded the "traumatic" stories compared to those preceding neutral stories. Participants with high trait dissociation showed relatively stronger perceptual perceptual priming. The degree of perceptual priming for stimuli from the "traumatic" stories also correlated with state dissociation (Experiment 1). Experimental manipulation of the elaboration of the stories showed that elaboration reduced the enhanced perceptual priming effect and the relative probability of reexperiencing symptoms (Experiment 2). The results support the role of perceptual priming in intrusions after traumatic events.     

Concept empiricism: a methodological critique

Thanks to Barsalou's, Damasio's, Glenberg's, Prinz' and others' work, neo-empiricism is gaining a deserved recognition in the psychology and philosophy of concepts. I argue, however, that neo-empiricists have underestimated the difficulty of providing evidence against the amodal approach to concepts and higher cognition. I highlight three key problems: the difficulty of sorting out amodal predictions from neo-empiricist predictions, the difficulty of finding experimental tasks that are not best solved by imagery and the difficulty of generalizing findings concerning a given cognitive process in a given context to other cognitive processes or other contexts. Finally, solutions to these three problems are considered.     

Distinguishing familiarity from fluency for the compound word pair effect in associative recognition

We examined whether processing fluency contributes to associative recognition of unitized pre-experimental associations. In Experiments 1A and 1B, we minimized perceptual fluency by presenting each word of pairs on separate screens at both study and test, yet the compound word (CW) effect (i.e., hit and false-alarm rates greater for CW pairs with no difference in discrimination) did not reduce. In Experiments 2A and 2B, conceptual fluency was examined by comparing transparent (e.g., hand bag) and opaque (e.g., rag time) CW pairs in lexical decision and associative recognition tasks. Lexical decision was faster for transparent CWs (Experiment 2A) but in associative recognition, the CW effect did not differ by CW pair type (Experiment 2B). In Experiments 3A and 3B, we examined whether priming that increases processing fluency would influence the CW effect. In Experiment 3A, CW and non-compound word pairs were preceded with matched and mismatched primes at test in an associative recognition task. In Experiment 3B, only transparent and opaque CW pairs were presented. Results showed that presenting matched versus mismatched primes at test did not influence the CW effect. The CW effect in yes-no associative recognition is due to reliance on enhanced familiarity of unitized CW pairs.     

CAN WE STILL TALK ABOUT “TRUTH” AND “PROGRESS” IN INTERDISCIPLINARY THINKING TODAY?

On a cultural level, and for Christian theology as part of a long tradition in the evolution of religion, evolutionary epistemology “sets the stage,” as it were, for understanding the deep evolutionary impact of our ancestral history on the evolution of culture, and eventually on the evolution of disciplinary and interdisciplinary reflection. In the process of the evolution of human knowledge, our interpreted experiences and expectations of the world (and of the ultimate questions we humans typically pose to the world) have a central role to play. What evolutionary epistemology also shows us is that we humans can indeed take on cognitive goals and ideals that cannot be explained or justified in terms of survival‐promotion or reproductive advantage only. Therefore, once the capacities for rational knowledge, moral sensibility, aesthetic appreciation of beauty, and the propensity for religious belief have emerged in our biological history, they cannot be explained only in biological/evolutionary terms. Finally, in this way a door is opened for seeing problem solving as a central activity of our research traditions. As philosophers of science have argued, one of the most important shared rational resources between even widely divergent disciplines is problem solving as the most central and defining activity of all research traditions. As will become clear, the very diverse reasoning strategies of theology and the sciences clearly overlap in their shared quests for intelligible problem solving, including problem solving on an empirical, experiential, and conceptual level.     

FAITH,BELIEF, AND THE COMPATIBILITY OF RELIGION AND SCIENCE

Recent attacks on the compatibility of science and religion by the “militant modern atheists” (Jerry Coyne, Richard Dawkins, Daniel Dennett, Sam Harris, Christopher Hitchens) have posed serious challenges for anyone who supports the human importance of religious faith (particularly their identification of “faith” with “believing without evidence”). This article offers a critical analysis of their claims compared with those who do not equate faith with belief. I conclude that (i) the militant modern atheist interpretation of faith undervalues transformative religious experiences, (ii) that more people of faith hold it for this reason than their opponents acknowledge, and (iii) that meaningful dialogue between religion and science is both possible and desirable.     

Motion-induced blindness does not affect the formation of negative afterimages

Aftereffects induced by invisible stimuli constitute a powerful tool to investigate what type of neural information processing can occur in the absence of visual awareness. This approach has been successfully used to demonstrate that awareness of oriented gratings or translating stimuli is not necessary to obtain a robust orientation-specific or motion-specific aftereffect. We exploit motion-induced blindness (MIB, Bonneh, Cooperman, & Sagi, 2001) to investigate the related question of the influence of visual awareness on the formation of negative afterimages. Our results show that MIB does not affect the persistence and intensity of afterimages. Thus, there is no significant contribution to the formation of afterimages beyond the sites mediating MIB.     

Playing on the typewriter, typing on the piano: manipulation knowledge of objects

Two experiments investigated sensory/motor-based functional knowledge of man-made objects: manipulation features associated with the actual usage of objects. In Experiment 1, a series of prime-target pairs was presented auditorily, and participants were asked to make a lexical decision on the target word. Participants made a significantly faster decision about the target word (e.g. ‘typewriter’) following a related prime that shared manipulation features with the target (e.g. ‘piano’) than an unrelated prime (e.g. ‘blanket’). In Experiment 2, participants' eye movements were monitored when they viewed a visual display on a computer screen while listening to a concurrent auditory input. Participants were instructed to simply identify the auditory input and touch the corresponding object on the computer display. Participants fixated an object picture (e.g. “typewriter”) related to a target word (e.g. ‘piano’) significantly more often than an unrelated object picture (e.g. “bucket”) as well as a visually matched control (e.g. “couch”). Results of the two experiments suggest that manipulation knowledge of words is retrieved without conscious effort and that manipulation knowledge constitutes a part of the lexical-semantic representation of objects.     

The interplay between perceptual organization and categorization in the representation of complex visual patterns by young infants

The relation between perceptual organization and categorization processes in 3- and 4-month-olds was explored. The question was whether an invariant part abstracted during category learning could interfere with Gestalt organizational processes. A 2003 study by Quinn and Schyns had reported that an initial category familiarization experience in which infants were presented with visual patterns consisting of a pacman shape and a complex polygon could interfere with infants' subsequent good continuation-based parsing of a circle from visual patterns consisting of a circle and a complex polygon. However, an alternative noninterference explanation for the results was possible because the pacman had been presented with greater frequency and duration than had the circle. The current study repeated Quinn and Schyns's procedure but provided an equivalent number of familiarization trials and duration of study time for the infants to process the pacman during initial familiarization and the circle during subsequent familiarization. The results replicated the previous findings of Quinn and Schyns. The data are consistent with the interference account and suggest that a cognitive system of adaptable feature creation can take precedence over organizational principles with which a perceptual system comes pre-equipped.     

Developmental changes in the processing of hierarchical shapes continue into adolescence

The present study was designed to trace the normal development of local and global processing of hierarchical visual forms. We presented pairs of hierarchical shapes to children and adults and asked them to indicate whether the two shapes were the same or different at either the global or the local level. In Experiments 1 (6-year-olds, 10-year-olds, adults) and 2 (10-year-olds, 14-year-olds, adults), we presented stimuli centrally. All age groups responded faster on global trials than local trials (global precedence effect), but the bias was stronger in children and diminished to the adult level between 10 and 14 years of age. In Experiment 3 (10-year-olds, 14-year-olds, adults), we presented stimuli in the left or right visual field so that they were transmitted first to the contralateral hemisphere. All age groups responded faster on local trials when stimuli were presented in the right visual field (left hemisphere); reaction times on global trials were independent of visual field. The results of Experiment 3 suggest that by 10 years of age the hemispheres have adult-like specialization for the processing of hierarchical shapes, at least when attention is directed to the global versus local level. Nevertheless, their greater bias in Experiments 1 and 2 suggests that 10-year-olds are less able than adults to modulate attention to the output from local versus global channels-perhaps because they are less able to ignore distractors and perhaps because the cerebral hemispheres are less able to engage in parallel processing.     

Developmental changes in face processing skills

Expertise in processing differences among faces in the spacing among facial features (second-order relations) is slower to develop than expertise in processing the shape of individual features or the shape of the external contour. To determine the impact of the slow development of sensitivity to second-order relations on various face-processing skills, we developed five computerized tasks that require matching faces on the basis of identity (with changed facial expression or head orientation), facial expression, gaze direction, and sound being spoken. In Experiment 1, we evaluated the influence of second-order relations on performance on each task by presenting them to adults (N=48) who viewed the faces either upright or inverted. Previous studies have shown that inversion has a larger effect on tasks that require processing the spacing among features than it does on tasks that can be solved by processing the shape of individual features. Adults showed an inversion effect for only one task: matching facial identity when there was a change in head orientation. In Experiment 2, we administered the same tasks to children aged 6, 8, and 10 years (N=72). Compared to adults, 6-year-olds made more errors on every task and 8-year-olds made more errors on three of the five tasks: matching direction of gaze and the two facial identity tasks. Ten-year-olds made more errors than adults on only one task: matching facial identity when there was a change in head orientation (e.g., from frontal to tilted up). Together, the results indicate that the slow development of sensitivity to second-order relations causes children to be especially poor at recognizing the identity of a face when it is seen in a new orientation.