Plurality of Viual Mismatch Potentials in a Reptile

Studies with auditory stimuli have established in humans that a mismatch potential (MMP) is elicited whenever a deviant stimulus is substituted for a standard stimulus in a train of monotonous standard stimuli presented at rates > 0.25 Hz. The MMP in humans is localized in the auditory cortex and is known as mismatch negativily, from its polarity in scalp recordings. It is hypothesized to reflect the operation of sensory memory and to be a necessary component of the auditory orienting response. To examine the generality of MMPs we used a visual mismatch paradigm with pond turtles (Pseudemys scripta) while recording with electrode arrays (200 m spacing) from near surface and deep visual projection areas within the forebrain and optic tectum. Standard stimuli were 10-sec trains of diffused strobe flashes presented at rates of 1-6 Hz against backgrounds of 2-11 lux. Deviant stimuli were brighter or dimmer flashes that followed the last standard flash. MMps were separated from visual evoked potentials by subtracting the response to the last standard flash of the train from the response to the same flash (bright or dim) when delivered as a deviant. Comparisons were also made with evoked potentials to isolated bright or dim flashes, that is, equal in frequency (1 per 12 sec) to the deviants but without intervening standard flashes. At tectal loci bright and dim deviants elicited net positivities that reached statistical significance in the period between 141 8 and 184 12 msec after the deviant stimulus (mean SEM). Earlier components in the tectal responses correlated with the intensity of the stimulus rather than its deviance. In the case of the bright deviants the early waves (P50-P75) were larger in amplitude. Forebrain recordings showed a similar although broader period of net positivity, associated with deviance, between 129 8 and 195 12 msec. Deviants, delivered as isolated flash responses evoked larger early components (100-140 msec). In separate experiments with cortical epipial electrodes, a condition somewhat more comparable to scalp recording, MMPs were similar in latency but had a negative polarity. Regression analyses revealed a relationship between the amplitude (base-to-peak) of the MMF' and the degree to which the standard response had declined with repeated stimulation. Rate decrement, as measured by the isolated (long ISI) flash response minus the last standard response, was a significant predictor of MMP amplitudes (r2 = 0.37, tectum; r2 = 0.31, forebrain), whereas standard response amplitudes alone were not (r2 = 0.09; r2 = 0.06). MMPs are present in nonmammals plurally, that is, at different levels of the visual system, at least as early as the tectum. The existence of subcortical MMPs caution against assigning a primary or exclusive role to those recorded from the cortex.

[1]  M Molnár,et al.  Evoked potential correlates of stimulus deviance during wakefulness and sleep in cat--animal model of mismatch negativity. , 1987, Electroencephalography and clinical neurophysiology.

[2]  R. Northcutt,et al.  Visual activity in the telencephalon of the painted turtle,Chrysemys picta , 1983, Brain Research.

[3]  T H Bullock,et al.  Event-related potentials in the retina and optic tectum of fish. , 1990, Journal of neurophysiology.

[4]  T. Picton,et al.  The N1 wave of the human electric and magnetic response to sound: a review and an analysis of the component structure. , 1987, Psychophysiology.

[5]  C. Shagass,et al.  CHAPTER 9 – Do Human Evoked Potentials Habituate? , 1984 .

[6]  W. D. Neff,et al.  Role of auditory cortex in discrimination of changes in frequency. , 1957, Journal of neurophysiology.

[7]  R. Näätänen,et al.  Stimulus deviance and evoked potentials , 1982, Biological Psychology.

[8]  K. Reinikainen,et al.  Do event-related potentials reveal the mechanism of the auditory sensory memory in the human brain? , 1989, Neuroscience Letters.

[9]  Steven A. Hillyard,et al.  The effect of stimulus deviation on P3 waves to easily recognized stimuli , 1978, Neuropsychologia.

[10]  R. Näätänen The role of attention in auditory information processing as revealed by event-related potentials and other brain measures of cognitive function , 1990, Behavioral and Brain Sciences.

[11]  F. Plum,et al.  Persistent vegetative state after brain damage. A syndrome in search of a name. , 1972, Lancet.

[12]  R. Desimone,et al.  A neural mechanism for working and recognition memory in inferior temporal cortex. , 1991, Science.

[13]  T. Bullock,et al.  Dynamic properties of visual evoked potentials in the tectum of cartilaginous and bony fishes, with neuroethological implications. , 1990, The Journal of experimental zoology. Supplement : published under auspices of the American Society of Zoologists and the Division of Comparative Physiology and Biochemistry.

[14]  K. Wise,et al.  Silicon ribbon cables for chronically implantable microelectrode arrays , 1994, IEEE Transactions on Biomedical Engineering.

[15]  G Nyman,et al.  Mismatch negativity (MMN) for sequences of auditory and visual stimuli: evidence for a mechanism specific to the auditory modality. , 1990, Electroencephalography and clinical neurophysiology.

[16]  D. J. Felleman,et al.  Distributed hierarchical processing in the primate cerebral cortex. , 1991, Cerebral cortex.

[17]  R. Näätänen,et al.  The duration of a neuronal trace of an auditory stimulus as indicated by event-related potentials , 1987, Biological Psychology.

[18]  S. Hillyard,et al.  The effects of channel-selective attention on the mismatch negativity wave elicited by deviant tones. , 1991, Psychophysiology.

[19]  S. Hillyard,et al.  Long-latency evoked potentials to irrelevant, deviant stimuli. , 1976, Behavioral biology.

[20]  A. Reiner,et al.  A comparison of neurotransmitter-specific and neuropeptide-specific neuronal cell types present in the dorsal cortex in turtles with those present in the isocortex in mammals: implications for the evolution of isocortex. , 1991, Brain, behavior and evolution.

[21]  I. Riches,et al.  The effects of visual stimulation and memory on neurons of the hippocampal formation and the neighboring parahippocampal gyrus and inferior temporal cortex of the primate , 1991, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[22]  H. Karten,et al.  The Origins of Neocortex: Connections and Lamination as Distinct Events in Evolution , 1989, Journal of Cognitive Neuroscience.

[23]  T H Bullock,et al.  Event-related potentials to omitted visual stimuli in a reptile. , 1994, Electroencephalography and clinical neurophysiology.

[24]  T H Bullock,et al.  Barbiturate sensitive components of visual ERPs in a reptile. , 1992, Neuroreport.