Effect of anesthetic drugs on time production and alpha rhythm

Ss produced time intervals before and during inhalation of low concentrations of anesthetic gases. The drugs increased time productions by raising the slope of the line representing produced against objective time. Alterations in time production were not accompanied by consistent changes in alpha rhythm, respiratory rate, heart rate, or body temperature. The findings argue against the’ alpha rhythm’s acting as the biological pendulum for the internal clock.     

Hospitalized psychiatric and medical patients and the clergy

Earlier research suggested that persons in a community with significant psychiatric disorders seek relief from their clergy as often as from trained mental-health professionals. In this research, contacts with clergy about current hospitalization by matched samples of inpatient psychiatric (N=51) and medical/surgical (N=50) patients were compared, as were responses to structured interviews about the importance of religion, religious affiliation, and participation, spiritual needs, and spiritual well-being. The findings suggest that the two groups were similar in demographics, the degree to which religion was a source of strength and comfort in their lives, and percentages reporting as having a clergy person; the group of hospitalized psychiatric patients was significantly less likely, however, than the sample of medical/surgical patients to have discussed their current hospitalization with their clergy persons. Possible causes for this difference as well as areas of further research are discussed.     

Selective perception by dynamic touch

Perceiving the length of a rod by dynamic touch is tied to the inertia tensorIij, a quantification of its resistance to rotational acceleration. Perception of the portion extending in front of the grasp has previously been ascribed to decomposing one component ofIij by attention. The tensorial nature of dynamic touch suggests that this ability must be anchored wholly in the tensor. Three experiments show that perceived partial length is a function of two components of the tensor, one tied primarily to magnitude and the other tied primarily to direction, whereas perceived whole length is a function of a magnitude component alone. Dynamic touch is characterized in terms of a haptic perceptual instrument that softly assembles to exploitIij differently depending on the intention, producing 1:1 maps that are appropriately scaled for each intention.     

Prime time advertisements: Repetition priming from faces seen on subject recruitment posters

Repetition priming is defined as a gain in item recognition after previous exposure. Repetition priming of face recognition has been shown to last for several months, despite contamination by everyday exposure to both experimental and control faces in the interval. Here we show that gains in face recognition in the laboratory are found from faces initially seen in a rather different context— on subject recruitment posters, even when the advertisements make no specific mention of experiments involving face recognition. The priming was greatest when identical pictures were shown in the posters and in the test phase, although different views of faces did give significant priming in one study. Follow-up studies revealed poor explicit memory for the faces shown on the posters. The results of these experiments are used to develop a model in which repetition priming reflects the process of updating representations of familiar faces.     

The importance of ‘mass’ in line drawings of faces

Previous research (Davies, Ellis and Shepherd, 1978; Rhodes, Brennan and Carey, 1987) has shown that accurate line drawings of familiar faces are identified rather poorly. However, artists can produce lifelike portraits with pen and ink, and Pearson and Robinson (1985) described an automatic method for producing computer-drawn sketches (‘cartoons’) of faces which appear very similar to those produced by a human artist. In this paper we show that subjects can identify famous faces depicted in such computer-drawn ‘cartoons’ almost as well as full grey-scale images. The cartoon algorithm comprises two components. One component draws lines at the locations of intensity changes corresponding to luminance valleys and edges (the ‘valledge’ detector). The other component applies a ‘threshold’ to the original intensity distribution, and replaces any area darker than threshold with black. Thus the full cartoon contains both ‘line’ and ‘mass’. Neither the valledges nor the threshold components alone were as well identified as full cartoons containing both components. The results suggest that the addition of the threshold component adds significantly to the identifiability of line drawings of faces.     

The role of spatially selective attention in the tactile perception of texture

During manual sensing of object attributes like surface texture, the tactile receptor sheet is conjointly activated at numerous loci. What is the role of spatially selective attention in perception under these conditions? We show that the requirement for spatial focus of attention is minimal in the detection of an abrupt change in texture. In contrast, spatial attention may help in a variety of other tasks of comparable difficulty. These include detecting the absence of a texture change at one of many loci, distinguishing its direction, and discriminating between different textures. Attentional demand appears to vary along a continuum in these tasks, rather than being all-or-none.     

The role of spatially selective attention in the tactile perception of texture.

During manual sensing of object attributes like surface texture, the tactile receptor sheet is conjointly activated at numerous loci. What is the role of spatially selective attention in perception under these conditions? We show that the requirement for spatial focus of attention is minimal in the detection of an abrupt change in texture. In contrast, spatial attention may help in a variety of other tasks of comparable difficulty. These include detecting the absence of a texture change at one of many loci, distinguishing its direction, and discriminating between different textures. Attentional demand appears to vary along a continuum in these tasks, rather than being all-or-none.     

Selective attention in vibrotactile tasks: detecting the presence and absence of amplitude change

Selective spatial attention has a greater effect on detection of the absence of an amplitude change than it has on detection of the presence of such a change. Attention to one of four fingertips was manipulated by an 80% valid tactile cue in two-interval forced-choice tasks. In one task, the target was a vibrotactile amplitude change appearing among constant-amplitude distractors; in the other task, targets of constant amplitude had to be detected amid amplitude changes at the other fingertips. Cuing had a greater effect on the latter task than it did on the former. This asymmetry is consistent with the presence-absence asymmetry found in visual search and does not depend on the difficulty of the two tasks. A statistical model shows that a pooled activity mechanism could account for these experimental results.