Contrasting Effects of Letter-spacing in Alexia: Further Evidence that Different Strategies Generate Word Length Effects in Reading

The reading behaviour of two alexic patients (SA and WH) is reported. Both patients are severely impaired at reading single words, and both show abnormally strong effects of word length when reading. These two symptoms are characteristic of letter-by-letter reading. Experiment 1 examined the pattern of errors when the patients read large and small words. Further experiments examined the effects of inter-letter spacing on word naming (Experiments 2a and 2b) and the identification of letters in letter strings (Experiment 3). For both patients, letter identification was better for widely spaced letters in letter strings, and this effect was most pronounced for the central letters in the strings. This is consistent with abnormally strong flanker interference in letter identification. However, inter-letter spacing affected word reading behaviour in the two patients in different ways. SA's word reading improved with widely spaced letters; WH's word reading was disrupted. This suggests that these patients adopted different strategies when reading words. We conclude that several reading behaviours can elicit word length effects, and that these different behaviours can reflect strategic adaptation to a common functional deficit in patients. We discuss the implications both for understanding alexia and for models of normal word identification.     

Functional imaging of the semantic system: retrieval of sensory-experienced and verbally learned knowledge

This paper considers how functional neuro-imaging can be used to investigate the organization of the semantic system and the limitations associated with this technique. The majority of the functional imaging studies of the semantic system have looked for divisions by varying stimulus category. These studies have led to divergent results and no clear anatomical hypotheses have emerged to account for the dissociations seen in behavioral studies. Only a few functional imaging studies have used task as a variable to differentiate the neural correlates of semantic features more directly. We extend these findings by presenting a new study that contrasts tasks that differentially weight sensory (color and taste) and verbally learned (origin) semantic features. Irrespective of the type of semantic feature retrieved, a common semantic system was activated as demonstrated in many previous studies. In addition, the retrieval of verbally learned, but not sensory-experienced, features enhanced activation in medial and lateral posterior parietal areas. We attribute these "verbally learned" effects to differences in retrieval strategy and conclude that evidence for segregation of semantic features at an anatomical level remains weak. We believe that functional imaging has the potential to increase our understanding of the neuronal infrastructure that sustains semantic processing but progress may require multiple experiments until a consistent explanatory framework emerges.     

Mood acknowledgment and correction for the mood-congruency bias in social judgment

Past research has revealed a mood-congruency bias wherein people evaluate other individuals more positively when they are experiencing good moods than when they are experiencing bad moods. At times, however, people may attempt to prevent their transient mood states from biasing their evaluations of other people. It was proposed that the capacity to attend openly to one’s moods is an important precursor to such mood correction efforts. Two studies supported this hypothesis. People who were encouraged to attend to their feelings (Study 1), as well as people who are naturally inclined to acknowledge their feelings (Study 2), were more likely than their counterparts to prevent their positive and negative moods from biasing their judgments of a target person.     

Lexical effects on speech perception in individuals with "autistic" traits

It has been claimed that Autism Spectrum Disorder (ASD) is characterized by a limited ability to process perceptual stimuli in reference to the contextual information of the percept. Such a connection between a nonholistic processing style and behavioral traits associated with ASD is thought to exist also within the neurotypical population albeit in a more subtle way. We examined this hypothesis with respect to auditory speech perception, by testing whether the extent to which phonetic categorization shifts to make the percept a known word (i.e., the 'Ganong effect') is weakened as a function of autistic traits in neurotypicals. Fifty-five university students were given the Autism-Spectrum Quotient (AQ) and a segment identification test using two word-to-nonword Voice Onset Time (VOT) continua (kiss-giss and gift-kift). A significant negative correlation was found between the total AQ score and the identification shift that occurred between the continua. The AQ score did not correlate with scores on separately administered VOT discrimination, auditory lexical decision, or verbal IQ, thus ruling out enhanced auditory sensitivity, slower lexical access or verbal intelligence as explanations of the AQ-related shift in phonetic categorization.