P. Hull Smith

Observer accuracy and observer agreement in the measurement of visual fixation with fixed-trial procedures

Abstract Forty-eight pairs of observers recorded fixations during three test sessions. In each session an adult subject executed a predetermined sequence of fixations for 15 20-s trials. Three factors were investigated: Viewing Condition (live vs. videotaped subject). Number of Stimulus Apertures (1, 2, 4) and Subject Eye Color (blue, brown). Results indicated that training procedures which focus on observer agreement generally lead to acceptable levels of accuracy. However, certain procedural variations affect observer accuracy and observer agreement in different ways. Likewise, certain experimental procedures are particularly demanding in terms of observer accuracy.

Infant Response to Facelike Patterns under Fixed-Trial and Infant-Control Procedures.

10-week-old infants were shown 4 facelike patterns that differed along 2 dimensions: number of elements and the extent to which the elements were organized to resemble the human face. The purpose was to determine whether the stimulus dimension to which infants respond is different with fixed-trial than with infant-control methodologies. Each infant was tested under 1 of 3 experimental conditions: fixed trials (trials and intervals of fixed, predetermined durations), offset control (trial termination controlled by the behavior of the infant), or onset-offset control (trial initiation and termination both controlled by the infants behavior). Although the relationship was linear with fixed trials and offset control but was curvilinear with onset-offset control, infants responded to number, rather than organization, of elements in all 3 conditions. Furthermore, no specific methodological advantages were demonstrated for infant-control procedures.

Five-Month-Old Infant Recall and Utilization of Temporal Organization.

Abstract The ability of 5-month-old infants to recall temporal information and utilize temporal organization was investigated in two experiments. Infants were trained to fixate a hierarchically structured or an unstructured sequence of stimuli which appeared in four spatial positions. In the first study, the number of infants who demonstrated correct recall through the third serial position of a sequence was significantly better then would occur by chance. In the second study, infants given structured sequences showed a significant increase in the number of correct fixations across trials, and they recalled across serial positions better in structured sequences. Also, accuracy of recall in both studies for the middle serial positions was related to hierarchical organization following 8-unit structured sequence training but was at chance level following unstructured sequence training. Results of both studies were interpreted within a temporal organizational framework: Infants appear to utilize organization within sequences of information.

Identity in Adolescence: Influences of Dysfunction and Psychosocial Task Issues.

The Erikson Psychosocial Stage Inventory (EPSI) was utilized in two studies to investigate task resolutions (trust, autonomy, initiative, industry, identity) in adolescence. In the first study, a comparison of delinquents and non-delinquents indicated that delinquents have less successful task resolutions. In the second study, a comparison of adolescents with high and low dysfunctional attitudes again revealed that troubled adolescents have less successful task resolutions. In this study, 7th graders, 12th graders, first-year college students, and junior and senior college students participated. Older adolescents demonstrated more successful task resolutions than younger adolescents, and different identity issues were salient during early adolescence as compared to later adolescence. Also, first-year college students had more problems with identity consolidation and less positive overall task resolutions than high school seniors or college juniors and seniors. A life-context approach to identity formation is discussed.

Expectancies and memory for spatiotemporal events in 5-month-old infants.

Five-month-old infants were trained to fixate four event locations, and recall was assessed following training in three experiments. Memory for four events was demonstrated in the first two studies, and memory for these events was also found to be robust following a 6- to 7-day delay. Infants demonstrated that they can anticipate upcoming events during training: they increased anticipatory behaviors during latter training trials, and they appeared to form expectancies of future events during periods of both stimulus onset and stimulus offset. Results are interpreted as consistent with a script representational view of memory for spatiotemporal events.