Biomedical subjects

S Dopkins

Publications and source records attributed to S Dopkins.

12 recordsLinked to original sources

PubMed2001

The contribution of category relationships to similarity ratings.

Two experiments produced evidence that category relationships contribute to similarity ratings. In Experiment 1, participants gave similarity ratings with respect to a semantic category (VEGETABLE) and a set of exemplars, some of which were members of the category (e.g., BROCCOLI) and some of which were not (e.g., BANANA). A regression analysis was used to predict the similarity ratings in terms of numbers of common and distinctive features, as reported by other participants. Perceived similarity was greater for examplars that were members of the category, independently of feature overlap. Experiment 2 examined similarity ratings with respect to pairs of exemplars. In some cases, both exemplars were members of the same category (e.g., BROCCOLI/CUCUMBER). In other cases, one exemplar was a member of the category and the other was not (e.g., BROCCOLI/BANANA). A regression analysis was used to predict the similarity ratings in terms of numbers of common and distinctive features. Perceived similarity was greater when both exemplars were members of the same category, independently of feature overlap.

Association↗

PubMed2001

Words in a sentence become less accessible when an anaphor is resolved.

A noun that identifies an entity in a discourse becomes less accessible following an anaphoric reference to another entity. The phenomenon cannot be attributed to ad hoc strategies, memory decay, or context checking. It occurs for both common and proper nouns and for nouns that identify both characters and inanimate objects. It is stronger for nouns that identify important entities, as opposed to more peripheral ones.

Cognition↗

PubMed2001

Memory for content and source in temporal lobe patients.

Left and right temporal lobectomy patients and normal controls were tested in a memory task for which the to-be-remembered items were simple actions involving small objects. Participants either performed the actions, perceived the experimenter performing the actions, or imagined themselves performing the actions. The patients were deficient relative to the controls at remembering the actions and at remembering whether the actions were performed, perceived, or imagined. These results are interpreted as suggesting that the temporal lobes are involved in memory for the source as well as the content of past experiences.

Adolescent↗

PubMed1997

Access to information about famous individuals in Alzheimer's disease.

Alzheimer's disease (AD) patients and normal adults were tested in two complementary recognition tasks. On each trial of the faces task, participants matched the photograph of a famous individual to one of four names. On each tial of the names task, participants matched the name of a famous individual to one of four photographs. The AD patients made enough consistent errors across the two tasks to suggest an impairment in the storage of information about the individuals. In addition, they made enough inconsistent errors to suggest a generalized retrieval deficit. The AD patients performed as well on the faces taslk as on the names task, providing no evidence of a specialized deficit in the retrieval of lexical information.

Adult↗

PubMed1997

Text representations as reflected in patterns of cognitive distance.

Subjects performed a task that involved learning a text and then indicating, for each of a series of pairs of words, whether they belonged to the same sentence of that text. When the principle of argument overlap or causal coherence was the sole integrative factor in a text, negative response times and error rates reflected distances in the network representation predicted by the principle. When the two principles predicted conflicting representations for a text, response times and error rates reflected the predictions of the principle of argument overlap. The results were interpreted as suggesting that network connections predicted by the two principles are both present in the memory representations of texts and that causal connections are recorded at a more abstract level or representation than are argument overlap connections.

Adult↗

PubMed1994

Frequency judgments for semantic categories in amnesics and normal controls.

Korsakoff's amnesics and normal controls read descriptions of five famous and five unknown individuals. Each individual was linked with five exemplars of one semantic category and three of another. Subjects decided which of the two relevant categories had been linked more frequently with each individual and made recognition judgments with respect to the exemplars. An analysis of the relationship between recognition and frequency judgment performance suggested that the normals but not the amnesics had used explicit memory for the exemplars in making their frequency judgments. An analysis of frequency judgment performance suggested that the judgments of the amnesics but not the normals reflected implicit memory for the associations between the individuals and the categories that had been used to describe them.

Alcohol Amnestic Disorder↗

PubMed1994

Role of an abstract order schema in conceptual judgment.

Ss performed same-different judgments for which order information was logically irrelevant. In Experiments 1 and 2, the stimuli for the judgment task were derived from an ordered set of concepts from long-term memory (U.S. presidents ordered on the dimension of historical time); in Experiments 3 and 4 the stimuli were derived from two ordered sets of concepts. In the stimulus set for each experiment, there were several associate phrases for each concept and the task was to judge whether the phrases were paired with the same concept (Experiments 1, 2, and 3) or the same ordering (Experiment 4). The time to respond "different" decreased with the ordinal distance between the concepts even when the concepts belonged to different orderings. It is concluded that same-different judgments are based in part on amodal order information (i.e., not tied to any particular dimension). Two models of the implicated order schema are proposed and tested.

Humans↗

PubMed1993

Accessibility of information about goals during the processing of narrative texts.

We used a probe procedure to show that a goal established earlier in a text is active in memory at the point of its achievement. An initial experiment demonstrated that a goal category (began an investigation to nab the THIEF) is accessible, relative to a control condition, following the processing of a goal-achievement sentence (had the PURSER brought to his office). The remaining experiments provided evidence against several explanations of this result: (a) that the goal category's accessibility is due to an advantage in the strength of its initial encoding; (b) that the goal category is maintained in memory from the point at which the goal is established; or (c) that the goal category is reinstated at the point of goal achievement as the result of a high-level inference. The results suggest that the goal category is reinstated as the result of a low-level inference similar to the type that links an anaphor and its antecedent.

Achievement↗

PubMed1993

Connecting goals and actions during reading.

Three experiments showed that reading about a character's actions can reactivate a goal of the character stated earlier in the passage and backgrounded by intervening material. Subjects were slower to read a line describing an action that was inconsistent with a goal of the protagonist than they were to read about an action that was consistent with the goal, even though both lines were locally coherent. Goals were reactivated even when the intervening material did not describe attempts to achieve the goal (Experiment 2) and when the intervening material described another goal of the protagonist (Experiment 3). The results suggest that reading a sentence can reactivate relevant information from earlier in the text, even when the sentence is coherent with its immediate context and the reactivated information has been backgrounded by several lines of unrelated text.

Adult↗

PubMed1991

Psychiatric diagnoses in minority female adolescent suicide attempters.

Psychiatric diagnoses were examined using the Schedule for Affective Disorders and Schizophrenia for School-Aged Children semistructured interview among three groups of minority adolescent females aged 12 to 17:61 suicide attempters, 31 psychiatrically disturbed nonattempters, and 23 nonattempting, nondisturbed girls. Major or minor depressive disorder was found in 42% of the suicide attempters; conduct disorder in 46%; multiple diagnoses in 38%, no diagnosis in 13%. These rates were very similar to those found in disturbed nonattempters. Only one symptom, suicidal ideation, distinguished attempters from disturbed nonattempters, while many symptoms distinguished these two groups from nondisturbed nonattempters.

Adolescent↗

PubMed1990

Acquisition of a new color name in amnesics and normal controls.

Six Korsakoffs amnesics, three mixed amnesics, and eight normal controls were taught the meaning of "bice", the word for a particular shade of blue-green. The conceptual interpretation that the Korsakoffs developed for "bice" differed in three respects from the one that the controls developed. (1) Although both Korsakoffs and controls applied the term more liberally to pens than to other objects, two of the Korsakoffs showed an extreme form of this tendency. (2) The Korsakoffs tended to generalize more broadly along the spectral dimension in using the term. (3) Whereas there was a positive relationship, in the data for the controls, between measures of syntactic and semantic awareness concerning "bice", there was no such relationship in the Korsakoffs data. It was concluded that the Korsakoffs had difficulty mastering the new word, and difficulty specifically in integrating their representation for the word with the rest of their lexical knowledge.

Amnesia↗

PubMed1988

Effects of instructional set on amnesic recognition memory performance.

Tests that tapped memory for spatial location, temporal order, frequency of occurrence, and category membership were administered to a group of alcoholic Korsakoff patients, a group of mixed amnesic patients with primarily temporal lobe pathology, and a group of normal subjects. The four tests were administered with incidental as well as intentional learning conditions. All groups performed better in the intentional than the incidental condition of the category recognition test. None of the groups performed better in the intentional than the incidental conditions on any of the other tests. The data were interpreted as implying that amnesic patients do not benefit from intentional learning conditions in tests of memory for contextual stimuli.

Alcohol Amnestic Disorder↗