RESUMEN
Non-visual gaze patterns (NVGPs) involve saccades and fixations that spontaneously occur in cognitive activities that are not ostensibly visual. While reasons for their appearance remain obscure, convergent empirical evidence suggests that NVGPs change according to processing requirements of tasks. We examined NVPGs in tasks with long-term memory (LTM) and working memory (WM) requirements. Experiment 1 yielded significantly higher eye movement rate (EMR) in tasks requiring LTM search than in a WM task requiring maintenance of information. Experiment 2 manipulated accessibility of items in study-test episodic tasks using the levels of processing paradigm. EMR was high in episodic recall irrespective of item accessibility. Experiment 3 examined functional significance of saccades in LTM tasks. Voluntary saccadic suppression produced no evidence that saccades contribute to task performance. We discuss the apparent epiphenomenal nature of spontaneous saccades from an evolutionary perspective and outline a neuroanatomical model of the link between the saccadic and memory system.
Asunto(s)
Fijación Ocular , Memoria a Largo Plazo , Memoria a Corto Plazo , Movimientos Sacádicos , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Desempeño Psicomotor , Factores de Tiempo , Percepción Visual , Adulto JovenRESUMEN
It is not known why people move their eyes when engaged in non-visual cognition. The current study tested the hypothesis that differences in saccadic eye movement rate (EMR) during non-visual cognitive tasks reflect different requirements for searching long-term memory. Participants performed non-visual tasks requiring relatively low or high long-term memory retrieval while eye movements were recorded. In three experiments, EMR was substantially lower for low-retrieval than for high-retrieval tasks, including in an eyes closed condition in Experiment 3. Neither visual imagery nor between-task difficulty was related to EMR, although there was some evidence for a minor effect of within-task difficulty. Comparison of task-related EMRs to EMR during a no-task waiting period suggests that eye movements may be suppressed or activated depending on task requirements. We discuss a number of possible interpretations of saccadic eye movements during non-visual cognition and propose an evolutionary model that links these eye movements to memory search through an elaboration of circuitry involved in visual perception.
Asunto(s)
Memoria , Movimientos Sacádicos , Análisis de Varianza , Percepción Auditiva , Femenino , Humanos , Imágenes en Psicoterapia , Masculino , Recuerdo Mental , Modelos Neurológicos , Tiempo de Reacción , Vías Visuales/fisiologíaRESUMEN
OBJECTIVE: This study examined the utility of baseline psychomotor speed, measured with neuropsychological tests, to predict fluoxetine response in moderately depressed outpatients. The authors hypothesized that since psychomotor slowing in depressed patients has been linked to reduced dopaminergic neurotransmission, patients with slowing would be unresponsive to fluoxetine, a selective serotonin reuptake inhibitor. METHOD: After baseline neuropsychological testing, patients were treated openly with fluoxetine for 12 weeks. Thirty-seven patients completed the trial. RESULTS: Compared to the 25 patients who responded, the 12 patients who did not respond to fluoxetine exhibited significantly poorer performance in verbal fluency on the Controlled Oral Word Association Test FAS and in color naming on the Stroop Color and Word Test. In addition, the nonresponders tended to perform worse than the responders on the Stroop Color and Word Test reading subtest and the WAIS-III digit symbol subtest. Differential treatment response was specific to psychomotor speed because responders and nonresponders did not perform differently on tasks of executive functioning, attention, visuospatial functioning, or verbal intelligence. CONCLUSIONS: Psychomotor slowing may identify a subgroup of depressed patients who have a dopaminergic deficit that is unresponsive to fluoxetine monotherapy and who should therefore receive an alternative treatment.
Asunto(s)
Atención Ambulatoria , Trastorno Depresivo Mayor/tratamiento farmacológico , Fluoxetina/uso terapéutico , Pruebas Neuropsicológicas/estadística & datos numéricos , Desempeño Psicomotor/efectos de los fármacos , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Adolescente , Adulto , Anciano , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Dopamina/deficiencia , Dopamina/fisiología , Femenino , Fluoxetina/farmacología , Humanos , Masculino , Persona de Mediana Edad , Probabilidad , Escalas de Valoración Psiquiátrica , Desempeño Psicomotor/fisiología , Factores de Riesgo , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Índice de Severidad de la Enfermedad , Transmisión Sináptica/efectos de los fármacos , Resultado del TratamientoRESUMEN
A field experiment was conducted assessing the effects of interpersonal gaze upon helping behavior. Three hundred twenty men and women were approached by a male or female confederate with his arm in a sling who, upon dropping some coins, either looked or did not look at the bystander. The results indicated that gaze was associated with increased helping when both victim and bystander were female and decreased helping when the two were males. The findings of the study suggest that interpersonal gaze may be interpreted differently by the sexes during dyadic helping interactions.