Biomedical subjects

A H Reinhardt-Rutland

Publications and source records attributed to A H Reinhardt-Rutland.

At least 19 recordsLinked to original sources

PubMed2004

Viewing behaviour of spider phobics and non-phobics in the presence of threat and safety stimuli.

OBJECTIVES: To determine whether spider phobics and spider non-phobics differ in attending to threat and safety stimuli in close proximity, or spatially separated. METHOD: A sample group of 16 spider-phobic and 16 spider-non-phobic volunteers were drawn from a student population on the basis of their scores on Watts and Sharrock's Spider Phobia Questionnaire. Attention was assessed by way of participants' viewing behaviour using an ASL 501 head-mounted eye-tracking system. In a control condition, participants viewed a neutral stimulus (a TV video) in the absence of the threat stimulus. In two experimental conditions, the threat stimulus (a live Chilean rose tarantula) was introduced (a) immediately beside the safety stimulus (the only exit of the experimental room), or (b) away from the safety stimulus. RESULTS: In the experimental conditions, phobics reduced their viewing of the TV and increased their viewing of the tarantula and of the exit; the biggest changes occurred when tarantula and exit were together. Phobics also made more eye motions across the experimental room. CONCLUSION: Our results are consistent with previous research employing reaction time to a neutral stimulus as dependent measure. In addition, our results suggest that phobics scan the environment as part of safety behaviour. We suggest that exposure treatments to reduce spider phobia may be facilitated by encouraging patients to stop environmental scanning.

Adult↗

PubMed2003

Induced rotational motion with nonabutting inducing and induced stimuli: implications regarding two forms of induced motion.

Induced motion is the illusory motion of a static stimulus in the opposite direction to a moving stimulus. Two types of induced motion have been distinguished: (a) when the moving stimulus is distant from the static stimulus and undergoes overall displacement, and (b) when the moving stimulus is pattern viewed within fixed boundaries that abut the static stimulus. Explanations of the 1st type of induced motion refer to mediating phenomena, such as vection, whereas the 2nd type is attributed to local processing by motion-sensitive neurons. The present research was directed to a display that elicited induced rotational motion with the characteristics of both types of induced motion: the moving stimulus lay within fixed boundaries, but the inducing and induced stimuli were distant from each other. The author investigated the properties that distinguished the two types of induced motion. In 3 experiments, induced motion persisted indefinitely, interocular transfer of the aftereffect of induced motion was limited to about 20%, and the time-course of the aftereffect of induced motion could not be attributed to vection. Those results were consistent with fixed-boundary induced motion. However, they could not be explained by local processing. Instead, the results might reflect the detection of object motion within a complex flow-field that resulted from the observer's motion.

Humans↗

PubMed2001

The spectrally dependent monotic component in the decreasing-loudness aftereffect: implications for dynamic auditory localization.

Listeners exposed to a tone increasing in intensity report an aftereffect of decreasing loudness in a steady tone heard afterward. In the present study, the spectral dependence of the monotic decreasing-loudness aftereffect (adapting and testing 1 ear) was compared with (a) the spectral dependence of the interotic decreasing-loudness aftereffect (adapting 1 ear and testing the other ear) and (b) a non-adaptation control condition. The purpose was to test the hypothesis that the decreasing-loudness aftereffect may concern the sensory processing associated with dynamic localization. The hypothesis is based on two premises: (a) dynamic localization requires monaural sensory processing, and (b) sensory processing is reflected in spectral selectivity. Hence, the hypothesis would be supported if the monotic aftereffect were more spectrally dependent and stronger than the interotic aftereffect; A. H. Reinhardt-Rutland (1998) showed that the hypothesis is supported with regard to the related increasing-loudness aftereffect. Two listeners were exposed to a 1-kHz adapting stimulus. From responses of "growing softer" or "growing louder" to test stimuli changing in intensity, nulls were calculated; test carrier frequencies ranged from 0.5 kHz to 2 kHz. Confirming the hypothesis, the monotic aftereffect peaked at around the 1-kHz test carrier frequency. In contrast, the interotic aftereffect showed little evidence of spectrally dependent peaking. Except when test and adaptation carrier frequencies differed markedly, the interotic aftereffect was smaller than the monotic aftereffect.

Female↗

PubMed1999

The framing effect with rectangular and trapezoidal surfaces: actual and pictorial surface slant, frame orientation, and viewing condition.

The perceived slant of a surface relative to the frontal plane can be reduced when the surface is viewed through a frame between the observer and the surface. Aspects of this framing effect were investigated in three experiments in which observers judged the orientations-in-depth of rectangular and trapezoidal surfaces which were matched for pictorial depth. In experiments 1 and 2, viewing was stationary-monocular. In experiment 1, a frontal rectangular frame was present or absent during viewing. The perceived slants of the surfaces were reduced in the presence of the frame; the reduction for the trapezoidal surface was greater, suggesting that conflict in stimulus information contributes to the phenomenon. In experiment 2, the rectangular frame was either frontal or slanted; in a third condition, a frame was trapezoidal and frontal. The conditions all elicited similar results, suggesting that the framing effect is not explained by pictorial perception of the display, or by assimilation of the surface orientation to the frame orientation. In experiment 3, viewing was moving-monocular to introduce motion parallax; the framing effect was reduced, being appreciable only for a trapezoidal surface. The results are related to other phenomena in which depth perception of points in space tends towards a frontal plane; this frontal-plane tendency is attributed to heavy experimental demands, mainly concerning impoverished, conflicting, and distracting information.

Adolescent↗

PubMed1998

Increasing-loudness aftereffect following decreasing-intensity adaptation: spectral dependence in interotic and monotic testing.

Listening to decreasing intensity leads to illusory increasing loudness afterwards. Evidence suggests that this increasing-loudness aftereffect may have a sensory component concerned with dynamic localisation. This was tested by comparing the spectral dependence of monotic aftereffect (adapting and testing one ear) with the spectral dependence of interotic aftereffect (adapting one ear and testing the other ear). Existence of the proposed component implies that monotic aftereffect should be more spectrally dependent than interotic aftereffect. Three listeners were exposed to a 1 kHz adapting stimulus. From responses of "growing softer" or "growing louder" to test stimuli changing in intensity, nulls were calculated; test carrier frequencies ranged from 0.5 kHz to 2 kHz. Confirming the hypothesis, monotic aftereffect was about three times as strong as interotic aftereffect for the 1 kHz test carrier frequency, while monotic and interotic aftereffects were comparable in magnitude for test carrier frequencies below about 0.8 kHz and above about 1.2 kHz. The latter residual aftereffects are attributed to cognitive processing, perhaps concerning response bias. Sensitivity did not vary systematically across conditions; this is consistent with evidence that changing intensity entails mainly direct processing. The results cannot be attributed to the loudness adaptation elicited by steady stimuli.

Adaptation, Psychological↗

PubMed1998

Sensitivity in changing-loudness aftereffects as indicated by an adjustment procedure: implications regarding mechanisms.

The reduced sensitivity that accompanies some auditory aftereffects has been linked to sensory fatigue. However, changing-loudness aftereffects are unaffected by reduced sensitivity, according to previous evidence from a single-interval forced-choice procedure. That result was confirmed in the present study, in which an adjustment procedure was used to measure changing-loudness aftereffects. In each condition, the listener set the rate of intensity change in test stimuli until they were heard as steady in loudness. The mean of 10 such settings was taken as a measure of the aftereffect's magnitude. The standard deviation of the 10 settings indicated the listener's sensitivity in perceiving changing intensity: The greater the standard deviation, the less the sensitivity. Consistent with previous data, the magnitude of increasing-loudness aftereffects (Experiment 1) and decreasing-loudness aftereffects (Experiment 2) varied according to the adaptation condition, but sensitivity did not. Although sensory fatigue may contribute to aftereffects, the author concluded that reduced sensitivity is not a reflection of sensory fatigue. Instead, it may be explained as a methodological artifact dependent on whether the adapted property is processed by direct or indirect mechanisms. Aftereffects only concern direct mechanisms, but the test stimuli used in their measurement may entail both types of mechanisms: If the measurement entails both types of mechanisms, sensitivity is reduced; if not, sensitivity is unaltered.

Adaptation, Psychological↗

PubMed1997

Changing-loudness aftereffects: slope of response functions and spectral dependence.

Aftereffects of azimuthal auditory motion may have two components. A sensory component is inferred from strong aftereffects, because they are spectrally dependent and have shallower response functions than those for non-adaptation. Neither property applies to weak aftereffects, suggesting a cognitive component. Two experiments determined whether changing-loudness aftereffects (CLA) might be understood similarly. In a single-interval forced-choice procedure, listeners responded "growing softer" or "growing louder" to test stimuli changing in intensity. In Exp. 1, adapting and test stimuli were diotic and had the same 1-kHz sinusoidal carrier. Although response functions following adaptation were displaced from response functions for non-adaptation-indicating CLA-their slopes were broadly similar. In Exp. 2, stimuli were monotic; adapting frequency was 1 kHz and test frequencies were between 0.5 and 2.0 kHz. CLA was present in most adaptation conditions, but was strongest when the test frequency was 1.0 kHz; functions' slopes again evinced no systematic variation. The two-component hypothesis for CLA is supported by spectral dependence alone. It is argued that the slope of response functions is due to the nulling procedures for measuring auditory aftereffects. The slope depends on whether the adapted property is processed by "direct" and "indirect" mechanisms; aftereffects tap "direct" mechanisms alone, which may affect sensitivity during measurement.

Adult↗

PubMed1996

Depth judgments of triangular surfaces during moving monocular viewing.

When an observer judges the orientation in depth of a trapezoidal surface, the pictorial information of the surface is often more influential than motion information. Motion information might be more effective if pictorial information is simplified: this prompts the present study. Surfaces were triangular and pictorial information resided only in the visual lengths of the surfaces. In experiment 1, monocular observers viewed during head motions of 0 to 30 cm extent. Static judgments were somewhat dependent on visual length and tended to be frontal. Contrary to predictions, moving judgments were similarly affected: only 30 cm motion elicited near-veridical perception, as in previous studies with trapezoidal surfaces, although visual length had a residual effect. Experiment 2 involved investigation of whether visual length requires prior exposure to triangular surfaces to be effective; this was found not to be the case, which argues that observers rely on internal models of triangular surfaces. Depth perception appears to balance rapidity of processing against accuracy, in a way suggesting that 'direct' approaches are incomplete. Finally, it is argued that depth-from-motion simulations-influential in assertions that motion information is fully effective-depend on pictorial information.

Depth Perception↗

PubMed1996

Perceiving the orientation-in-depth of triangular surfaces: static-monocular, moving-monocular, and static-binocular viewing.

Although data from simulations suggest that motion information and binocular information each elicit veridical depth perception, data from real stimuli, such as trapezoidal surfaces, are equivocal; the discrepancy might be explained by the complexity of nonveridical pictorial information in the latter. In the present study, observers judged the orientations-in-depth of triangular surfaces about a vertical axis: Pictorial information resided only in the visual lengths of surfaces, so it was predicted that motion and binocularity would be fully effective. Viewing conditions were static-monocular (SM), moving-monocular (MM), and static-binocular (SB). SM judgments were largely frontal, reflecting the equidistance tendency that applies in impoverished conditions. SB judgments were broadly veridical, as predicted. However, MM judgments were only partly influenced by motion information; the equidistance tendency and visual length also contributed--the latter in contrast to SM. It is concluded that motion information is only weakly effective, no matter what the complexity of pictorial information. Instead, motion may be valuable in enhancing pictorial information.

Adolescent↗

PubMed1996

Asymmetrical perception of changing intensity in short tonal stimuli: duration of stimulus.

A number of reports have suggested that changing intensity in short tonal stimuli is asymmetrically perceived. In particular, steady stimuli may be heard as growing louder; stimuli must decrease in intensity to be heard as steady in loudness. The influence of stimulus duration on this perceptual asymmetry was examined. Three participants heard diotic tonal stimuli of eight durations between 0.8 s and 2.5 s. Each stimulus increased, decreased, or remained steady in intensity; initial intensity was 40 dB SPL (sound pressure level relative to 0.0002 dynes/cm2), and carrier frequency was 1 kHz. Participants made forced binary responses of "growing louder" or "growing softer" to each stimulus. For each duration, that value of intensity change eliciting equal numbers of both responses was determined. The results indicated a pronounced perceptual asymmetry for 0.8-s stimuli, which diminished for longer stimuli; changing intensity in 2.5-s stimuli was perceived symmetrically. Additionally, sensitivity to changing intensity improved as stimulus duration increased, suggesting that responses may be based in part on the difference in intensity between the beginning and end of the stimulus. Possible ramifications of the asymmetry reside in (a) the percussive nature of many natural sounds and (b) selective responding to approaching sound sources.

Adult↗

PubMed1996

Remote operation: a selective review of research into visual depth perception.

Some perceptual motor operations are performed remotely; examples include the handling of life-threatening materials and surgical procedures. A camera conveys the site of operation to a TV monitor, so depth perception relies mainly on pictorial information, perhaps with enhancement of the occlusion cue by motion. However, motion information such as motion parallax is not likely to be important. The effectiveness of pictorial information is diminished by monocular and binocular information conveying flatness of the screen and by difficulties in scaling: Only a degree of relative depth can be conveyed. Furthermore, pictorial information can mislead. Depth perception is probably adequate in remote operation, if target objects are well separated, with well-defined edges and familiar shapes. Stereoscopic viewing systems are being developed to introduce binocular information to remote operation. However, stereoscopic viewing is problematic because binocular disparity conflicts with convergence and monocular information. An alternative strategy to improve precision in remote operation may be to rely on individuals who lack binocular function: There is redundancy in depth information, and such individuals seem to compensate for the lack of binocular function.

Depth Perception↗

PubMed1996

The illusion of increasing loudness in brief steady tones: variation with carrier frequency.

A brief tone of steady intensity is heard as growing louder; to be heard as steady, intensity must be decreasing. The present report concerns the influence of carrier frequency on this illusion. Stimuli each lasted 1.5 s, during which time intensity was increasing, decreasing, or remaining steady; the initial intensity was 40 dB SPL (sound pressure level relative to 0.0002 dynes/cm2). Carrier frequencies were between 0.0625 and 8.0 kHz. Four listeners made forced binary responses of "growing louder" or "growing softer" to stimuli. Values of changing intensity that elicited equal numbers of each type of response were computed. As expected, these values were negative. The illusion was most pronounced for the lowest and highest frequencies. In contrast to the results of a recent study, the findings were that sensitivity to changing intensity did not vary systematically with the size of the illusion. The illusion might arise because many sounds slowly decay in intensity and because of the importance of detecting approaching sound sources, analogous to "looming" in the visual modality. Overall loudness of the sound source should assist in altering the listener; the increase in the illusion at the extremities of the frequency range might compensate for the reduced overall loudness at such frequencies.

Adult↗

PubMed1996

A cross-modal aftereffect: auditory displacement following adaptation to visual motion.

It has been shown earlier that the perceived location of static sound-sources can be displaced (a) during visual motion and (b) following auditory motion. Here we combine these phenomena. The subject adapted to the horizontal visual motion of a surrounding drum, then (with the lights off) localized static sound-sources by setting the direction of a pointer. Adapting motion was clockwise or counterclockwise: the difference between each subject's settings following the opposite directions of adaptation showed small but consistent auditory displacements opposite to the adapting directions. This visual-auditory aftereffect, which is consistent with sensorineural data, challenges a general, if implicit, belief that aftereffects do not cross modalities.

Adolescent↗

PubMed1996

The growing-louder effect in short diotic stimuli.

Previous evidence from short monotic stimuli shows that a steady stimulus is perceived as growing louder; to be perceived as steady, the intensity of the stimulus must decrease. In the present study, 10 subjects heard a sequence of diotic tonal stimuli. Each stimulus lasted 1.5 sec. and increased, decreased, or remained steady in intensity; initial intensity was 40 dB SPL and carrier frequency was 1 kHz. Subjects made forced binary responses of "growing louder" or "growing softer" to each stimulus. Confirming the evidence from monotic stimuli, the mean value of changing intensity eliciting equal numbers of both responses was negative. Possible explanations for this growing-louder effect reside in (a) the percussive nature of many natural sounds and (b) selective responding to approaching sound-sources.

Adult↗

PubMed1995

Perceiving the orientation in depth of real surfaces: background pattern affects motion and pictorial information.

Motion information contributes weakly to veridical depth perception of real stimuli. To test whether background pattern might enhance veridicality, observers judged the orientations in depth of pictorially matched trapezoidal and rectangular surfaces, with and without a rectangular grid of vertical stripes in a frontal plane behind surfaces; viewing was monocular with lateral head motions of 15 cm extent. The grid did not enhance veridicality; instead, surfaces actually or pictorially slanted to the frontal plane were judged more slanted with the grid present. In a second experiment, observers were static or moved through 30 cm; the grid had little effect during stasis, but again elicited judgments of greater slant during motion, despite broadly veridical responses without the grid. Results from actual slant are interpreted in terms of motion contrast and suggest that motion information may be important in conveying differences in orientation. Results from pictorial slant suggest that the influence of pictorial information increases as its complexity increases.

Adult↗

PubMed1995

Evidence for frequency-dependent and frequency-independent components in increasing- and decreasing-loudness aftereffects.

Listening to a decreasingly intense tone leads to increasing loudness in a subsequent steady tone. Conversely, listening to an increasingly intense tone leads to decreasing loudness in a subsequent steady tone. Measurement entails a test stimulus changing in sound level to null any aftereffect, so that loudness is perceived as steady. Previous studies have shown that the aftereffects are frequency dependent: Carrier frequencies of adapting and test stimuli must be closely matched for the greatest aftereffects. In the present study, frequency-independent components were also indicated: Despite separation between adapting and test frequencies of up to two octaves, measurements always differed after decreasing and increasing sound-level adaptation, such that frequency functions for the two directions of adaptation never crossed. According to evidence from other negative adaptation effects in the auditory modality, explanation of the present aftereffects requires at least two mechanisms: Frequency-dependent components may reflect sensory processing, whereas frequency-independent components may be nonsensory in origin.

Attention↗

PubMed1995

Increasing- and decreasing-loudness aftereffects: asymmetrical functions for absolute rate of sound level change in adapting stimulus.

After exposure to a tone of decreasing sound level, participants report that a steady tone increases in loudness; after exposure to an increasing sound level, they perceive a steady tone to decrease in loudness. The increasing-loudness aftereffect is the more sensitive to a difference between adapting and test frequencies, its absolute size becoming greater than that for decreasing-loudness aftereffect as frequencies are made to match. Although this asymmetry may reflect processing differences for the two directions of sound level change, a more parsimonious hypothesis entails perceived increasing loudness of short steady tones, in conjunction with differing levels of tonal adaptation across test frequencies. The former explanation is supported by the present report of another aftereffect asymmetry: With frequency the same for both adapting and test stimuli, so that tonal adaptation was nearly asymptotic during testing, altering the absolute rate of sound level change of the adapting stimulus had a greater effect on the magnitude of the increasing-loudness aftereffect. The first hypothesis is consistent with the percussive nature of natural sounds, few of which are steady: most of their sound levels rise almost instantaneously and decrease slowly.

Humans↗

PubMed1995

The influence of onset sound level of test stimulus on reported magnitude of changing-loudness aftereffects.

An increasing-loudness aftereffect follows adaptation to a tone of decreasing sound level; a decreasing-loudness aftereffect follows adaptation to a tone of increasing sound level. Contrary to the belief that sensory processing contributes to these changing-loudness aftereffects, evidence suggests that onset sound level of test stimulus may have little influence on reported aftereffects. This was tested formally in the present study. Adapting stimuli and test stimuli all employed 1-kHz sinusoidal carriers: Three onset sound levels of test stimuli were well within the range of sound levels encompassed by adapting stimuli; a fourth was set at the highest value of this range. Consistent with previous evidence, substantial aftereffects were reported for all the midrange onset sound levels, with little difference across onset sound levels. However, for the high-range onset sound level, reported aftereffects were severely attenuated. Sensory processing can be invoked by supposing that aftereffect mechanisms "tap" neural activity that encodes adapting sound levels.

Humans↗