Judging psychopathology: Expectation and contrast

An experiment was performed to assess the role of expectations in psychosocial contrast effects. Subjects were initially presented with a series of word definitions that were either high or low pathology; their task was to indicate those definitions that had been produced by schizophrenic (vs nonschizophrenic) patients. After this “induction” series, subjects were presented with a common “test” series that included both definitions and handwriting samples; they evaluated the degree of psychopathology that was implied by each item. Some subjects were required to state their expectations in connection with the test items. First they attempted to guess the percentage of schizophrenics in the overall test series; second, before being presented with each test item, they guessed whether the patient in question was (or was not) schizophrenic. Subjects' expectations were consistent with the induction series to which they were assigned; those assigned to the high-pathology induction expected the test series to include more schizophrenic patients than those in the low-pathology group. Nonetheless, despite these expectations, subjects showed a contrast effect in their evaluations of the test definitions (but not in evaluating the handwriting samples). That is, subjects from the low-pathology induction group rated the test definitions as being more pathological than did those in the high-pathology condition. Within-group correlations indicated that the subjects' expectations were directly related to subsequent judgments. A two-path model is discussed, relating (a) the respondents' induction group assignment, (b) his/her expectations, and (c) subsequent test judgments.     

Processing of identity and position information in normal and disabled readers

Processing of identity and position information was investigated in normal and disabled readers at two grade levels (third/fourth grade and sixth grade). Two partial-report tasks were used. The identity task consisted of visual presentation of a five-letter array, followed by a probe letter. Subjects responded yes for a match and no for a mismatch (identity response). The identity + position task was identical except that an additional response was required on correct yes trials: subjects reported the position of the probe letter in the array (position response). Both grade level and reading ability differences were found on the identity response measure, but not on the position response measure. Results were inconsistent with the hypothesis that disabled readers have difficulties in processing order information. Reader ability differences in identity processing attenuated somewhat with age. Serial position functions for both identity and position responses suggested the presence of a left-to-right scanning operation in both age and ability groups. Reader ability differences in processing letter identities were discussed in the context of current theories of reading acquisition.     

Specificity in contrast effects: Judgments of psychopathology

Three experiments were conducted to explore the specificity of the contrast effect in judgments of psychopathology. In the first two studies, respondents initially attempted to infer whether each item in a series of behavior samples (vocabulary definitions in one study, handwriting samples in the second) came from a schizophrenic or a nonschizophrenic patient. Some respondents were presented with highly pathological samples in this induction series, while others were presented with relatively nonpathological samples. These divergent experiences led to marked contrast effects in evaluating test stimuli from the same behavioral domain (e.g., additional vocabulary definitions), but had significantly less impact on the respondent's reactions to stimuli from a different domain (e.g., handwriting samples). A third experiment yielded similar results, using a paired-comparison methodology. In this study subjects first judged a series of high- vs low-pathology definitions. They were then presented with a series of matched stimulus pairs, each including one vocabulary definition and one hand-writing sample. Respondents were to indicate the member of each pair that seemed more indicative of schizophrenia. People assigned to the high-pathology induction group typically chose the handwriting samples as being more indicative of schizophrenia, compared with respondents who were assigned to the low-pathology conditions. These results were interpreted as supporting a representational (perceptual) theory of contrast.