Recognition memory for objects in very young children: The effect of shape and label similarity on preference for novel stimuli

In two studies, 88 children 12 to 38 months of age were briefly shown 24 common objects on familiarization trials. On subsequent test trials, these objects reappeared paired with novel objects. On one-third of the test trials pairs were similar in shape, on another third of the test trials pairs shared a common label, and on the remaining test trials pairs were unrelated. Looking times for each of the two objects on test trials were measured. All but the youngest age group showed significantly longer looking times for novel than for familiar objects for all three kinds of test pairs. However, for 19- to 31-month-olds preference for novel stimuli in the common Label Condition, although significant, was less than preference for novel stimuli when shape was similar or when unrelated stimuli were paired. Recognition in the oldest group was unaffected by condition. The results suggest a developmental period during which label or conceptual similarity has a special significance for recognition, and are discussed within theoretical frameworks concerning the very young child's developing semantic and categorization skills.     

Drug-induced amnesia impairs implicit relational memory

Amnesic patients have difficulty consciously recollecting past events, but they perform normally on implicit memory measures that do not require conscious access. Now, an innovative study offers compelling evidence that even implicit memory can be impaired during amnesia, temporarily induced in healthy subjects using a neuropharmacological manipulation (midazolam). Importantly, midazolam impaired implicit, relational memory, whereas non-relational memory was preserved, supporting the characterization of conscious memory in terms of relational encoding.     

Concurrent measurement of heart rate and instrumental avoidance behavior in the Rhesus monkey

A graphical method has been developed for the concurrent recording of heart beats and lever responses during behavioral experiments. The EKG signal fed into any DC amplifier goes to a fixed level trigger circuit and relay driver with its own power supply. The signal from this drives any standard cumulative recorder. Lever response rates are recorded concurrently on an additional cumulative recorder using the same paper speed.     

Development of a complex multiple schedule in the chimpanzee

The development of chimpanzee behavior on a four-component, three-lever multiple schedule is described. Component schedules included the Sidman avoidance procedure with a concurrent discriminated avoidance schedule on a second lever, fixed ratio performance for food, differential reinforcement of low rate for water requiring a dual response chain, and a symbol discrimination task for continuous food reinforcement using three levers. The avoidance component of this schedule was employed during the January 31, 1961 suborbital space flight of the chimpanzee “Ham.” On November 29, 1961, the chimpanzee “Enos” performed on the multiple schedule during three orbits around the earth in a Mercury capsule.     

Broad or narrow affect scores for the Multiple Affect Adjective Check List? Comment on Hunsley's “dimensionality of the Multiple Affect Adjective Check List-Revised”

Hunsley's paper constitutes the second independent replication of four of the five factors in the Multiple Affect Adjective Check List-Revised (MAACL-R), even though he used the trait instead of the state form used to construct the scales and a more stringent factor loading criterion than Zuckerman and Lubin. Hunsley also did a two-factor analysis (positive and negative affects) of the MAACL items and concluded on the basis of the scree test that this was a more optimal solution than the five-factor one. This conclusion is questioned on the basis that the scales were devised to improve discriminant validity of the subscales, which they have done, particularly if standard scores are used. Since four of the five factors are replicable in state and trait versions of the MAACL-R and clinical studies show discriminant validity for the subscales, there is no reason to ignore the components of the two broader affect factors. Such factors can be assessed through use of the two standard summary scores for the MAACL: Dysphoria (A + D + H) and Positive Affect plus Sensation Seeking (PA + SS).