Perception of the Body in Space: Mechanisms

Young, Laurence R.

doi:10.1002/cphy.cp010322

Cited by 90 publications

(69 citation statements)

References 114 publications

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“…The cab and /or the pointer could be moved at constant velocity (cab, 3 cm /sec in the experimental field; pointer, 2.5 mm /sec on the LCD monitor) in all directions during continuous manipulation of the joystick by the monkey. Acceleration of the cab was 4.5 cm /sec 2 to reach a constant velocity (i.e., 3.0 cm /sec), which was comparable to or below the vestibular threshold for humans (Young, 1984;Gianna et al, 1996). The movement direction of the cab and /or the pointer was linked to the direction to which the joystick was brought down by the monkey.…”

Section: Animals and E Xperimental Apparatusmentioning

confidence: 80%

“…Other descriptions as in Figure 3. physiological studies in monkeys reported that the HF neurons responded to whole-body motion and view but not to place (O'Mara et al, 1994;Rolls and O'Mara, 1995). Because the cab moved at very slow speed (i.e., 3 cm /sec) with very slow acceleration (i.e., 4.5 cm /sec 2 ), which was comparable to or below the vestibular thresholds for humans (Young, 1984;Gianna et al, 1996), the HF neurons showing place fields in the RT tasks seemed not to respond to whole-body motion in the present study. Also, the HF and PH neurons consistently showed locationdifferential responses when the monkey went through the field with a different direction.…”

Section: Place Fields Of the Monkey Hf And Ph Neuronsmentioning

confidence: 90%

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Spatial- and Task-Dependent Neuronal Responses during Real and Virtual Translocation in the Monkey Hippocampal Formation

et al. 1999

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Neuropsychological data in humans demonstrated a pivotal role of the medial temporal lobe, including the hippocampal formation (HF) and the parahippocampal gyrus (PH), in allocentric (environment-centered) spatial learning and memory. In the present study, the functional significance of the monkey HF and PH neurons in allocentric spatial processing was analyzed during performance of the spatial tasks. In the tasks, the monkey either freely moved to one of four reward areas in the experimental field by driving a cab that the monkey rode (real translocation task) or freely moved a pointer to one of four reward areas on the monitor (virtual translocation task) by manipulating a joystick. Of 389 neurons recorded from the monkey HF and PH, 166 had place fields that displayed increased activity in a specific area in the experimental field and/or on the monitor (location-differential neurons). More HF and PH neurons responded in the real translocation task. These neurons had low mean spontaneous firing rates (0.96 spikes/sec), similar to those of rodent HF place cells. The remaining nonresponsive neurons had significantly higher mean firing rates (8.39 spikes/ sec), similar to interneurons or cells in the rodent HF. Furthermore, most location-differential neurons showed different responses in different tasks. These results suggest that the HF and PH are crucial in allocentric information processing and, moreover, that the HF can encode different reference frames that are context or task-dependent. This may be the neural basis of episodic memory.

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Section: Animals and E Xperimental Apparatusmentioning

confidence: 80%

Section: Place Fields Of the Monkey Hf And Ph Neuronsmentioning

confidence: 90%

Spatial- and Task-Dependent Neuronal Responses during Real and Virtual Translocation in the Monkey Hippocampal Formation

et al. 1999

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“…It has been suggested that the GIF is disambiguated based on its frequency content (Paige and Tomko 1991;Telford et al 1997) with low-frequency shifts in the GIF interpreted as tilt and higher frequencies shifts interpreted as translation. Conversely, because head movements typically activate the canals and alter visual orientation cues, a second hypothesis is that the brain's estimates of head orientation and motion are based on a central synthesis of gravitoinertial and nonotolithic afferent signals Young 1984). In rhesus monkeys, numerous eye movement studies are consistent with the sensory synthesis hypothesis as vestibular-mediated eye movements appear to result from an interaction between the rotational cues derived from the canals and the GIF information transduced by the otoliths (e.g., Angelaki et al 1999).…”

Section: Introductionmentioning

confidence: 99%

Roll Tilt Psychophysics in Rhesus Monkeys During Vestibular and Visual Stimulation

Lewis

Haburcakova²,

Merfeld³

2008

Journal of Neurophysiology

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Lewis RF, Haburcakova C, Merfeld DM. Rolt tilt psychophysics in rhesus monkeys during vestibular and visual stimulation. J Neurophysiol 100: 140 -153, 2008. First published April 16, 2008 doi:10.1152/jn.01012.2007. How does the brain calculate the spatial orientation of the head relative to gravity? Psychophysical measurements are critical to investigate this question, but such measurements have been limited to humans. In non-human primates, behavioral measures have focused on vestibular-mediated eye movements, which do not reflect percepts of head orientation. We have therefore developed a method to measure tilt perception in monkeys, derived from the subjective visual vertical (SVV) task. Two rhesus monkeys were trained to align a light bar parallel to gravity and performed this task during roll tilts, centrifugation, and roll optokinetic stimulation. The monkeys accurately aligned the light bar with gravity during static roll tilts but also demonstrated small orientation-dependent misperceptions of the tilt angle analogous to those measured in humans. When the gravito-inertial force (GIF) rotated dynamically in the roll plane, SVV responses remained closely aligned with the GIF during roll tilt of the head (coplanar canal rotational cues present), lagged slightly behind the GIF during variable-radius centrifugation (no canal cues present), and shifted gradually during fixed-radius centrifugation (orthogonal yaw canal cues present). SVV responses also deviated away from the earth-vertical during roll optokinetic stimulation. These results demonstrate that rotational cues derived from the semicircular canals and visual system have prominent effects on psychophysical measurements of roll tilt in rhesus monkeys and therefore suggest that a central synthesis of graviceptive and rotational cues contributes to percepts of head orientation relative to gravity in non-human primates.

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“…Psychophysical studies have demonstrated that the estimate of the vertical in man depends on a weighed combination of labyrinthine gravitoinertial cues, as well as visual and somatosensory cues (Mittelstaedt, 1983;Young, 1984;Jeannerod & Biguer, 1987). Conflicting information coming from different sensors can result in substantial tilts of the perceived vertical and in corresponding changes of body posture.…”

Section: Body Schemementioning

confidence: 99%

The control of limb geometry in cat posture.

Lacquaniti

Taillanter

Lopiano

et al. 1990

The Journal of Physiology

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SUMMARY1. The aim of this study is to address the problem of the controlled variable in quadrupedal stance. In particular, we considered whether the projection of the centre of mass of the body on the support surface or the joint torques or the geometrical configuration of the limbs are primarily controlled.2. Cats were trained to stand freely on a platform which could be tilted in the sagittal plane by up to + 20 deg. The normal and tangential components of the contact forces at each paw were measured by means of load cells. The position of limb joints was recorded by means of the ELITE system.3. The projection of the centre of body mass on the platform, as well as the orientation and length of limb axes, varied to only a limited extent with tilt angle. In particular, the limb axes were closely lined up with the vertical, as were the vectors of the contact forces at the paws. As a result, the torques at the proximal joints (scapula and hip) were close to zero and the torques at the other joints varied little with table tilt.4. In order to test the different hypotheses on postural control, an external load (10-20% of the animal weight) was applied to the cat forequarters. The projected centre of mass consistently shifted forwards, contrary to the hypothesis that this parameter is controlled in stance. Instead, the geometry of limb posture remained unmodified after load application, even though the torques at forelimb joints were much greater than in the control.5. This postural behaviour showed no sign of adaptation over a period of 24 h of continuous load application.6. It is concluded that limb geometry is primarily controlled in stance. The results are discussed in the context of current notions on hierarchical control and body scheme.

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Perception of the Body in Space: Mechanisms

Cited by 90 publications

References 114 publications

Spatial- and Task-Dependent Neuronal Responses during Real and Virtual Translocation in the Monkey Hippocampal Formation

Spatial- and Task-Dependent Neuronal Responses during Real and Virtual Translocation in the Monkey Hippocampal Formation

Roll Tilt Psychophysics in Rhesus Monkeys During Vestibular and Visual Stimulation

The control of limb geometry in cat posture.

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