The frequency effect for pseudowords in the lexical decision task

Four experiments were designed to investigate whether the frequency of words used to create pseudowords plays an important role in lexical decision. Computational models of the lexical decision task (e.g., the dual route cascaded model and the multiple read-out model) predict that latencies to low-frequency pseudowords should be faster than latencies to high-frequency pseudowords. Consistent with this prediction, results showed that when the pseudowords were created by replacing one internal letter of the base word (Experiments 1 and 3), high-frequency pseudowords yielded slower latencies than low-frequency pseudowords. However, this effect occurred only in the leading edge of the response time (RT) distributions. When the pseudowords were created by transposing two adjacent internal letters (Experiment 2), high-frequency pseudowords produced slower latencies in the leading edge and in the bulk of the RT distributions. These results suggest that transposed-letter pseudowords may be more similar to their base words than replacement-letter pseudowords. Finally, when participants performed a go/no-go lexical decision task with one-letter different pseudowords (Experiment 4), high-frequency pseudowords yielded substantially faster latencies than low-frequency pseudowords, which suggests that the lexical entries of high-frequency words can be verified earlier than the lexical entries of low-frequency words. The implications of these results for models of word recognition and lexical decision are discussed.     

Lateralization of squamous cell carcinomas in the head-neck region

Earlier studies have shown the lateralization of several immune disorders, including herpes zoster infection and breast cancer. We investigated whether there is lateralization of squamous cell carcinomas in the head-neck region and a relation of handedness with this cancer. Analysis showed right-sided lateralization of head-heck cancers in right-handed patients and vice versa in left-handed ones and a higher rate of left-handedness in patients with squamous cell cancer. Associations among left-handedness, squamous cell carcinoma, and its lateralization may result from a genetic togetherness.     

Emotion Socialization in Families of Children With an Anxiety Disorder

Compared emotion socialization in 26 children with anxiety disorders ages 8–12 years and their mothers to 26 nonclinical counterparts without psychopathology. Children and their mothers participated in an emotion interaction task in which they discussed occasions when the child felt worry, sadness, and anger. Responses were coded for length of discussion, proportion of words spoken by child vs. mother, frequency of positive and negative emotion words, explanatory discussion of emotion, and maternal facilitation of emotion discussion. Children and their mothers also completed the Expressiveness and Control scales of the Family Environment Scale. Results indicated that mothers of children with an anxiety disorder spoke less frequently than their child, used significantly fewer positive emotion words, and discouraged their childrens emotion discussions more than did mothers of nonclinical children. Nonclinical children and their mothers indicated significantly more emotional expressiveness in their families than did children with an anxiety disorder and their mothers. These results highlight the potential role of truncated family emotional expressivity in the emotional development and functioning of children with an anxiety disorder.     

Familiarity breeds distortion: the effects of media exposure on false reports concerning media coverage of the terrorist attacks in london on 7 July 2005

The present experiment investigated whether increased media exposure could lead to an increase in memory distortions regarding a traumatic public event: the explosion of the No. 30 bus in Tavistock Square, London on 7 July 2005. A total of 150 Swedish and 150 UK participants completed a series of questionnaires about their memory of either (i) the aftermath of the explosion, (ii) a non-existent computerised reconstruction of the moment of the explosion, or (iii) non-existent closed circuit television footage of the moment of the explosion. In line with the availability heuristic, U.K. participants were more likely than Swedish participants to claim to have seen all three types of footage. Furthermore, a subsample of U.K. participants who appeared to have developed false "memories" of seeing the No. 30 bus explode scored significantly higher on measures of dissociation and fantasy proneness than participants who did not develop false "memories". This experiment provides further support for the role of imaginative processes in the development of false memories.     

Recruitment of anterior and posterior structures in lexical-semantic processing: an fMRI study comparing implicit and explicit tasks

Previous studies examining explicit semantic processing have consistently shown activation of the left inferior frontal gyrus (IFG). In contrast, implicit semantic processing tasks have shown activation in posterior areas including the superior temporal gyrus (STG) and the middle temporal gyrus (MTG) with less consistent activation in the IFG. These results raise the question whether the functional role of the IFG is related to those processes needed to make a semantic decision or to processes involved in the extraction and analysis of meaning. This study examined neural activation patterns during a semantic judgment task requiring overt semantic analysis, and then compared these activation patterns to previously obtained results using the same semantically related and unrelated word pairs in a lexical decision task which required only implicit semantic processing (Rissman, J., Eliassen, J. C., & Blumstein, S. E. (2003). An event-related fMRI investigation of implicit semantic priming. Journal of Cognitive Neuroscience, 15, 1160-1175). The behavioral results demonstrated that the tasks were equivalent in difficulty. fMRI results indicated that the IFG and STG bilaterally showed greater activation for semantically unrelated than related word pairs across the two tasks. Comparison of the two task types across conditions revealed greater activation for the semantic judgment task only in the STG bilaterally and not in the IFG. These results suggest that the pre-frontal cortex is recruited similarly in the service of both the lexical decision and semantic judgment tasks. The increased activation in the STG in the semantic judgment task reflects the greater depth of semantic processing required in this task and indicates that the STG is not simply a passive store of lexical-semantic information but is involved in the active retrieval of this information.     

Effects of practice on variability, effects of variability on transfer

Five experiments examined how practice early in skill acquisition affected variability and accuracy during skill retention (Experiments 1-5) and skill transfer (Experiments 3, 4, 5). Lag constraints required that each path from apex to base of a computer-generated pyramid display differ from some number (the lag) of immediately prior paths. Location constraints specified end points at which paths must exit the pyramid. In all experiments, an early optimal period for acquiring a variability level was identified. Both low and high levels of variability were sustained during retention; high levels facilitated transfer. The results suggest that (a) early practice that requires high variability sensitizes learners to changes in condition and (b) such perception-performance links facilitate transfer by activating appropriate alternative strategies/schema or initiating their construction.     

Associative symmetry of the memory for object-location associations as revealed by the testing effect

The nature of episodic associations has been subject to a long standing debate, where the two opposing positions postulate associations as either a holistic representation of the constituent elements or as independently modifiable pointers between them. In spite of a history of inconsistent findings, evidence in favour of the theory of symmetric associations has accumulated, yet only for verbal memory [Caplan, J. B., Glaholt, M. G., & McIntosh, A. R. (2006). Linking associative and serial list memory: Pairs versus triples. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32(6), 1244-1265; Kahana, M. J. (2002). Associative symmetry and memory theory. Memory and Cognition, 30(6), 823-840]. Although object-location associations differ in several fundamental characteristics from verbal paired-associates, we recently found associative symmetry in the memory for this class of associations as well [Sommer, T., Rose, M., & Büchel, C. (2007). Associative symmetry vs. independent associations in the memory for object-location associations. Journal of Experimental Psychology: Learning, Memory, and Cognition, 33(1), 90-106]. Due to the inconsistencies in the verbal literature, we felt it to be pertinent to confirm this finding using another experimental approach. Based on recent advances in understanding the effects of successive testing, we were able to make use of this knowledge and introduce this effect as an experimental manipulation in the study of associative symmetry. In particular, we investigated whether the influence of a prior memory test on a subsequent memory test differs when the same or opposite constituent element of an object-location paired-associate cues the retrieval on each test. We observed an identical testing effect for both conditions, which was exclusively driven by reminiscence, the recovery of previously inaccessible information. This finding lends strong support in favour of holistically or symmetrically represented object-location associations and suggests, given the verbal memory literature, a general principle of associative symmetry [Asch, S. E., & Ebenholtz, S. M. (1962). The principle of associative symmetry. Proceedings of the American Philosophical Society, 106, 135-163].     

The effect of temporal and spatial frequency on phantom-contour detection

Phantom contours are a visual illusion that can define regions with distinctive boundaries when no real surrounding edges exist. Spatial-frequency sensitivity is known to vary reliably across the visual-processing pathways, as does temporal-frequency sensitivity. Given that the effect of temporal frequency on phantom-contour detection has been previously established, and that the relationship between spatial frequency and temporal frequency is known, two experiments were designed to measure the highest level of spatial frequency that would still allow reliable pattern detection at different temporal frequencies by using the phantom-contour paradigm. The results revealed that phantom-contour detection is impaired when the stimulus has a high spatial-frequency content and that phantom-contour perception is supported by low spatial frequencies.     

Inferences about the location of food in capuchin monkeys (Cebus apella) in two sensory modalities

The authors tested the ability of capuchin monkeys (Cebus apella) to make inferences about hidden food. In Experiment 1, we showed the content of 2 boxes, 1 of which was baited (visual condition, VC) or we shook both boxes producing noise from the baited box (auditory condition, AC). Seven subjects (out of 8) were above chance in the VC, whereas only 1 was above chance in AC. During treatment, by manipulating empty and filled objects subjects experienced the relation between noise and content. When tested again, 7 capuchins were above chance in the VC and 3 in AC. In Experiment 2, we gave visual or auditory information only about the empty box and, consequently, successful choice implied inferential reasoning. All subjects (out of 4) were above chance in the VC, and 2 in the AC. Control tests ruled out the possibility that success resulted from simply avoiding the shaken noiseless box, or from the use of arbitrary auditory information. Similar to apes (Call, 2004), capuchins were capable of inferential reasoning.     

When is motion 'motion'?

Examples of visual motion have become more and more abstract over the years, leading up to 'third-order' stimuli where direction is actually determined by the observer through top - down attention. But how far can this be pushed--are there motion stimuli that are yet more arbitrary and abstract? Actually, there is a broad class of 'conceptual motion' stimuli--things like a moving grating of faces, or a shifting pattern of words--that are perfect analogs to traditional 'perceptual motion' stimuli, solvable by the same motion computation and for which observers can readily make direction-of-motion judgments. Interestingly though, these do not produce a sensation of motion (among other automatic consequences of motion detection). Here we compare a luminance-based perceptual motion stimulus to a semantic-based conceptual motion stimulus to contrast the psychophysical hallmarks of these motion categories.