The use of an unpleasant sound as the unconditional stimulus in aversive Pavlovian conditioning experiments that involve children and adolescent participants

Ethical considerations can prohibit the use of traditional unconditional stimuli (USs), such as electric shocks or loud tones, when children or adolescents participate in aversive Pavlovian conditioning experiments. The present study evaluated whether an unpleasant sound provides a viable alternative. Fifteen boys and girls aged 13 to 17 years completed a differential Pavlovian conditioning procedure in which a conditional stimulus (CS) was followed by the sound of metal scraping on slate. Acquisition of conditioned responses was found in startle blink magnitude, expectancy judgments of the sound, and skin conductance responses. Extinction of conditioned responses was found in all measures when the CS was no longer followed by the unpleasant sound. Subjective ratings and skin conductance responses indicated that the sound was unpleasant because of its qualitative features, rather than its intensity. The results support the use of an unpleasant sound as a low-risk alternative to traditional USs in aversive Pavlovian conditioning experiments with children and adolescents.     

Idiom literality judgments in younger and older adults: age-related effects in resolving semantic interference

To study age effects in the resolution of idiomatic semantic ambiguity, we focus on decomposability, the extent to which a literal reading of an idiom's words shares meaning with its figurative interpretation. Younger and older adults judged whether decomposable and nondecomposable idioms and nonidioms had a literal interpretation. Older adults were slower at making literality judgments and more sensitive to conflicts between literal and figurative meanings. The results support claims of decompositional analysis of idioms during later processing stages and of obligatory activation of figurative meanings. They also lend support to research that has shown age-related effects in ambiguity resolution.     

Primary Progressive Aphasia: A Review of 112 Cases

Primary progressive aphasia (PPA) was first recognized by Mesulam in 1982. Although dozens of cases have since been described, it has been difficult to place these cases into a coherent framework due to the wide variation in measures which have been reported. We review 170 contacts with 112 patients to provide a clinical, neuroanatomical, and neuropsychological profile of patients with the disorder. The progression of the disease is analyzed over a 10-year reporting period starting from symptom onset to show how progression affects five general linguistic skills: oral and written naming, reading, repetition, and general comprehension. The pattern of functional and neurological deficits in PPA is heterogeneous. Differences in the distribution of neurological anomalies between patients with bilateral and unilateral changes suggest that there may be two separate disease processes involved.     

Word frequency effects in high-dimensional co-occurrence models: A new approach

The HAL (hyperspace analog to language) model of lexical semantics uses global word co-occurrence from a large corpus of text to calculate the distance between words in co-occurrence space. We have implemented a system called HiDEx (High Dimensional Explorer) that extends HAL in two ways: It removes unwanted influence of orthographic frequency from the measures of distance, and it finds the number of words within a certain distance of the word of interest (NCount, the number of neighbors). These two changes to the HAL model produce