Computers for cognitive research: A HyperCard adventure game

For researchers interested in exploring the cognitive and metacognitive processes involved in problem-solving, one obstacle has been the difficulty of creating engaging and ecologically valid situations in which to observe these skills in practice. Computer games can provide a rich environment for research on such skills. I present a HyperCard example of an adventure game that serves as an environment for research on analogy in problem-solving. The design of the game and interface is detailed, and initial results of and suggestions for extensions to this work are presented.     

Behavioral effects of microwave reinforcement schedules and variations in microwave intensity on albino rats

The objective of this exploratory investigation was to determine the interactive effects of fixed-ratio scheduling of microwave reinforcement in tandem with changes in microwave intensity. Nine albino rats were conditioned to regulate their thermal environment with microwave radiation while living in a Skinner (operant conditioning) Box in which the ambient temperature was about 27.13 degrees F at the beginning of the session. Each rat obtained a 6-sec. exposure of microwave radiation on a fixed-ratio schedule of MW reinforcement, the values of which varied from FR-1 to FR-30. Intensities of MW radiation were 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted for 8 to 9 hr. over an approximate 13-mo. period. The effects of the intensity of microwave reinforcement varied as a function of the ratio value of the schedule used. Continuous reinforcement (FR-1) produced the lowest over-all rates, whereas FR-15, and FR-25 produced the highest over-all rates. Relatively higher thermal-behavior rates occurred under 62.5 W than under any of the other MW intensities for FR-1, FR-15, and FR-25, whereas FR-10 and FR-30 ratios produced intermediate rates of thermal responding which were constant for all values of MW intensity. These data are explained in terms of interactive effects between the "local" satiation or deprivation properties of the MW intensity and the ratio requirements of the schedule of MW reinforcement.     

Behavioral thermoregulation with microwave radiation of albino rats

The objective of this exploratory study was to investigate the extent to which microwave radiation would reinforce operant behavior in a cold environment. A reversal-design with the single subject serving as its own control was used for testing the reinforcing properties of microwaves. Six albino rats were conditioned to produce 6-sec. pulses of microwave radiation within a refrigerated environment. The schedule of reinforcement was continuous (crf). Each lever press produced a 6-sec. output of microwave radiation. The intensity of radiation was varied across blocks of sessions in the reversal design. Microwave values used were as follows: 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted from 8 to 9 hr. over an approximate 7-mo. period. Results showed that rates of operant responding varied as a direct function of microwave intensity. Relatively high mean rates were associated with moderate microwave intensity (250 W), whereas lower mean rates of responding were associated with extreme microwave intensities (62.5 W and 437.5 W) in the reversal design. These data are explained in terms of satiation and deprivation of the reinforcing value of microwave radiation.     

The interval for interference in conscious visual imagery

Three experiments are described that use dynamic visual noise (DVN) to interfere with words processed under visual and verbal processing instructions. In Experiment 1 DVN is presented to coincide with the encoding of the words or to coincide with the interval between encoding and recall. The results show that while DVN is a robust disruptor when it is applied during encoding to words processed under visual instruction, it has no effect during encoding when the words are processed under rote instruction. Moreover, DVN has no effect when it is applied during the retention interval, no matter what means are employed to encode the words. Experiment 2 extends these findings by again showing no effect of DVN during the retention interval, yet showing robust interference effects for visually processed words during recall. Finally, Experiment 3 demonstrates that the results of Experiments 1 and 2 cannot be explained by a difference in the time duration associated with application of DVN during the retention interval compared to during encoding and recall. Moreover, the differing decay functions for visually and verbally processed words during the intervals used in Experiment 3 suggest that any failure to cause interference is not because the two processing instructions resulted in words being retained in the same medium. The functions are consistent with word storage mechanisms reflecting appropriately verbal and visual properties. The results are discussed in terms of current models of visual working memory. It is argued that a full interpretation of the results requires a buffer mechanism as an important component of any model of visual working memory.     

Three-month-olds, but not newborns, prefer own-race faces

Adults are sensitive to the physical differences that define ethnic groups. However, the age at which we become sensitive to ethnic differences is currently unclear. Our study aimed to clarify this by testing newborns and young infants for sensitivity to ethnicity using a visual preference (VP) paradigm. While newborn infants demonstrated no spontaneous preference for faces from either their own- or other-ethnic groups, 3-month-old infants demonstrated a significant preference for faces from their own-ethnic group. These results suggest that preferential selectivity based on ethnic differences is not present in the first days of life, but is learned within the first 3 months of life. The findings imply that adults' perceptions of ethnic differences are learned and derived from differences in exposure to own- versus other-race faces during early development.     

A portable,unobtrusive device for videorecording clinical interactions

Recording and analyzing real-time interactions in clinical settings is important for basic and applied research in psychology and other disciplines. Investigators frequently have used simple audiotaping procedures to record these encounters (e.g., Roter, Geller, Bernhardt, Larson, & Doksum, 1999), but videorecording is increasingly viewed as more reliable and valid, because it captures the full range of complex and interdependent verbal and nonverbal behaviors that occur in an interaction. This article describes a system designed to videotape clinical interactions in a manner that can be moved in and out of different clinical rooms to preserve flexibility in its use. Data are presented to demonstrate that the system is unobtrusive during the interaction, yet fully compatible with institutional review board guidelines to protect human participants’ privacy and freedom to control the recording process.     

Kinematic information feedback and task constraints

The experiments were designed to examine the effect of task constraints on the influence of kinematic information feedback to facilitate the acquisition of discrete arm movements. The findings of Experiments 1 and 3 revealed that when the criterion kinematic trajectory was an increasing acceleration function, the most effective control space representation for kinematic feedback (i.e. position-time; velocity-position) was the one that matched the error criterion to be minimized. Furthermore, in Experiment 1 the velocity-position feedback condition led to greater performance error than the discrete knowledge of results of movement time or integrated position-time error. Experiment 2 showed that kinematic information feedback of the movement trajectory (position-time; velocity-position) did not facilitate acquisition of a constant velocity criterion, in contrast to knowledge of results of movement time or integrated velocity-position error. Collectively the findings suggest that the interaction of task and organismic constraints dictates the nature of the information feedback required to facilitate the acquisition of skill. The augmented information available must match the degrees of freedom requiring constraint in the movement sequence.