Inattentive State Research Articles

Thalamic Burst Mode and Inattention in the Awake LGNd

Awake mammals are often inattentive in familiar environments, but must still respond appropriately to relevant visual stimulation. Such "inattentive vision" has received little study, perhaps due to difficulties in controlling eye position in this state. In rabbits, eye position is exceedingly stable in both alert and inattentive states. Here, we exploit this stability to examine temporal filtering of visual information in LGNd neurons as rabbits alternate between EEG-defined states. Within a single second of shifting from alert to an inattentive state, both peak temporal frequency and bandwidth were sharply reduced, and burst frequency increased dramatically. However, spatial dimensions of receptive field centers showed no significant state dependence. We conclude that extremely rapid and significant changes in temporal filtering and bursting occur in the LGNd as awake subjects shift between alert and inattentive states.

Reflections on Field Experience

Mr. Manafo provides 10 guidelines for preservice teachers who yearn for success in their field placements. Hello Future Teachers, While you are on your well-deserved break from classes and field placements, I thought I would take the opportunity to pull together some of my thoughts on field experience and pass them on to you. First, congratulations for getting off to a good start in your school. Almost without exception, your cooperating teachers are pleased with your performance over the past two weeks. In fact, most of them are positively glowing in their accounts of how well you are doing. Of course, that puts a certain pressure on you to continue at the same high level, but I am confident you can do this. Here are my thoughts: 1. As the weeks go by, resist the temptation to fall into comfortable modes in the classroom. Obviously, there are some things you enjoy doing more than others. However, field experience is as much a time to experiment as it is to practice and repeat typical behaviors. Yes, we all must correct papers - and, in fact, one can become a whiz with a red pen. But how about taking that student aside who just doesn't seem to get it and offering some creative insight? Your red pen will last that much longer. 2. Part of the process of experimentation is finding your as a teacher. Voice, in this context, is more than simply how you choose to modulate the sounds that come out of your mouth. It also has to do with how you choose to address the students, the rapport you establish with them, your body language, how you give positive reinforcement, and the ways you interact with other teachers and with parents. If you haven't a clue as to what your teacher voice is yet, don't despair. It can be developed with practice. Remember that smiles can work wonders and that, when you talk with youngsters or adults, you should look them squarely in the eyes. 3. I believe that observation is an art. We tend to think of observing as a passive activity in which one simply watches what is going on at a given time and place. But as many of you (especially those working with young children) have found out, just sitting around watching what goes on in the classroom can be next to impossible - especially if your cooperating is a progressive educator who believes in the value of hands-on experiences. You need to remind yourself to observe while in action. Are you aware of what other activities are going on in the class in addition to the one you are engaged in? Have you learned all the students' names yet? Are you keeping one eye on your cooperating to see how he or she is handling activities? You can learn to observe on the fly. Practice! It sure beats operating in a state of inattention. 4. I think having an outgoing, winning personality is a positive thing for a teacher. However, teachers come in as many personality types as do professionals in any other line of work. Just because you see yourself as tending toward the introspective, the quiet, or even the shy doesn't mean you can't become a first-rate teacher. Yes, you may have to work a little harder to develop your voice, but remember that young people need to associate with and learn from many different types of adults. Not everyone (in fact, hardly anyone) can be Mr. …

Contextual Effects in the Classroom: The Impact of Ability Groups on Student Attention

This study looks at contextual effects within the elementary classroom by examining the extent to which students' ability group assignments affect their rate of becoming inattentive. The data include behavioral measures of attentiveness obtained from 16 video-taped lessons of first grade reading groups. These data were analyzed using a continuous-time, stochastic model in which the dependent variable is an instantaneous rate of change from the state of attention to the state of inattention. Assignment to a low ability group was found to have a strong negative effect on student attentiveness, controlling for individual characteristics and previous individual inattention.

The effect of inattention on form perception.

A state of inattention was achieved by having subjects selectively attend to one of two overlapping novel figures in a series of such overlapping figures. Recognition of form directly afterward was good for figures that had been attended to but was essentially nil for the unattended figures. Recognition failed to occur even if a familiar figure was in the unattended series and even if that figure was presented 1 sec before the test. A further experiment showed that certain general characteristics of the unattended figures other than form were recognized. The results are interpreted as indicating that attention is necessary for form perception, not merely for memory of form. It is suggested that a cognitive process of description constitutes the essence of form perception. Diverting attention eliminates the cognitive operation of describing the spatial relations that characterize a figure.

The effect of inattention on form perception.

A state of inattention was achieved by having subjects selectively attend to one of two overlapping novel figures in a series of such overlapping figures. Recognition of form directly afterward was good for figures that had been attended to but was essentially nil for the unattended figures. Recognition failed to occur even if a familiar figure was in the unattended series and even if that figure was presented 1 sec before the test. A further experiment showed that certain general characteristics of the unattended figures other than form were recognized. The results are interpreted as indicating that attention is necessary for form perception, not merely for memory of form. It is suggested that a cognitive process of description constitutes the essence of form perception. Diverting attention eliminates the cognitive operation of describing the spatial relations that characterize a figure.

Re-examination of the effects of periodic and aperiodic stimulation on the auditory-evoked vertex response.

It has been hypothesized that aperiodic stimulation will produce larger auditory-evoked vertex responses than periodic stimulation. Attentiveness toward an acoustic stimulus by human subjects has been shown in the past to enhance the auditory-evoked response. The unpredictability of aperiodic intersignal intervals has been assumed by previous investigators to produce more attentive listening behaviour and has therefore been used clinically to obtain 'enhanced' evoked responses. In order to examine this question further, auditory-evoked vertex responses were obtained with variable-interval (aperiodic) and with fixed-interval (periodic) schedules of stimulus presentation that had geometric mean intersignal intervals of 5 or 10 s. The evoked responses were obtained from normally-hearing adults while they were engaged in a counting task and while they were reading. Tone bursts were presented at 30 and 60 dB sensation level. No significant differences in peak-to-peak amplitude measures of components with latencies shorter than 300 ms could be attributed to aperiodic stimulation. When the time-base on the signal averager was extended to include components with latencies longer than 300 ms, no significant changes in component amplitudes could be attibuted to aperiodic stimulation, even though peak-to peak amplitudes during an attentive state (counting) were nearly double those obtained during an inattentive state (reading). It was concluded that aperiodicity in intersignal intervals is not a useful technique to employ in order to produce larger and more identifiable evoked responses for clinical diagnosis.

Form perception without attention.

Methods were devised which made it possible for subjects to look directly at novel forms without attending to them. In one method a state of inattention was achieved without the use of distracting or competing material whereas in a second method the subjects selectively attended to one series of moving figures rather than another simultaneously presented series. While recognition of form directly afterward was excellent even under incidental conditions with attention it was poor or at a chance level without attention. The results suggest that without attention memory of the specific shape of a figure is not established although there is memory for certain other general characteristics of the figure. It is argued that this failure of adequate trace formation results from the failure to “describe” the spatial relations which characterize a figure. It is suggested that such a process of description constitutes the essence of form perception and does not occur without attention.

IMAGES AND MENTAL MAPS

ABSTRACT “Image'’and “mental map'’appear frequently in the literature of environmental perception, often in an abstract or metaphorical sense. As psychological phenomena mental images do not play any essential role in spatial behavior, nor in abstract thinking. To account for spatial ability we need to postulate “schemata,'’rather than images and mental maps. The mental map, a special kind of image, does have its functions: for example, it is a mnemonic device; it allows mental practice which promotes assurance in subsequent physical performance; it is, like the real map, a way to organize data; it is an imaginary world, complex and attractive enough to tempt people out of their habitual rounds. To generate images focal attention seems necessary. In an inattentive state, skillful behavior in space is still possible under the guidance of somatic intelligence or schemata.

A Plasma Model of Brain Dynamics

A plasma model of the brain is proposed to explain the long range correlations observed in the nervous system of the living brain and to understand such mental functions of the brain as the remembering (as well as forgetting) and the recalling of information received from the external world. In this model a waking but inattentive state of the brain is repre­ sented by a single-humped distribution function for the nerve cell activity (measured by the firing rate of bioelectrical impulses), and an attentive excited state brought about by an ex­ ternal stimulation by a distribution function with a small second hump on the tail. The quasi-linear approximation to the Liouville equation for the activity distribution function in the neural phase space predicts the flattening of the small hump and the formation of a plateau persisting for indefinitely long time, which is interpreted as the . memory process of the brain. The model is compared with the model of Ricciardi and Umezawa, in which the stable memory of the brain is related to the Bose condensation into the ground state of the qnan­ tum many-body system of Goldstone particles which are associated with the spontaneous breakdown of various symmetries in the brain.

The interaction of visual attention and temporal cortex stimulation on electrical activity evoked in the striate cortex

Four experiments were directed at finding an index of the activity of the infero-temporal (IT) cortex on the visual system. In the first experiment, electrical stimulation of the IT cortex failed to alter recovery functions in the striate cortex of four monkeys. This result was different from that reported in an earlier experiment, but comparison of the initial recovery functions obtained in the two experiments allowed us to attribute the discrepancy to differences in the attentional state of the monkeys. This suggestion was tested by developing, in the second experiment, a reliable measure of state in the visual system, a measure responsive to environmental variables inducing attention. This measure was used in the third experiment to select and classify recovery cycles on the basis of the state of the visual system. Only when the attentive state was present were the recovery cycles similar to those recorded in the first experiment. Finally, the measure, a potential evoked in the striate cortex by geniculate stimulation, was shown to be sensitive to IT stimulation only when monkeys were in an inattentive state.

The Rhythmic Activity of the Nervous System

While recent studies have shed some light on the significance of the electrical activity of the nervous system, there has been no adequate explanation for the wave formation or synchronization of this electrical activity. Adrian (1) sums up the problem. “The origin of the 10-a-second rhythm is still uncertain, though the evidence points to some widespread organization, probably involving the central masses as well as the cortex. There are abundant nervous connexions for coordinating the beat, and when the rhythm is well developed it is possible to record impulse discharges in phase with it passing to and fro in the nerve fibers of the white matter below the cortex. But in some areas no impulse could be detected entering or leaving the cell layers, though the potential waves keep more or less in step with those elsewhere. There is no proof that the waves are kept in phase by some means which does not involve nervous signalling, for impulses in axons of small diameter might well be missed, but it is not altogether unlikely that the synchronization is due in part to a direct electrical influence of one group of nerve cells on another. Gerard and Libet have shown that synchronization can occur between the two halves of a frog's brain cut in two and then placed in contact, and more recently Arvanitaki has shown that individual nerve cells may influence one another if they are brought close together in a conducting medium. At all events there are many examples of synchronized rhythmic activity in large collections of nerve-or-muscle cells. In the optic ganglion of the water beetle, for instance, there may be both a slow rhythm when the eye is in darkness and a rapid one when the eye is exposed to a bright light. The change from a slow to a fast rhythm is curiously reminiscent of that in the cerebral cortex when a sensory stimulus abolishes the 10-a-second rhythm and substitutes one at 40–60 a second. Such resemblances in preparations of quite different structures may be quite fortuitous, but they make it difficult to resist the suggestion that the rhythms of the brain may be dependent on the general properties of cell masses rather than on any special anatomical arrangement of them. Whatever its origin, the 10-a-second rhythm of the cortex corresponds to the resting, drowsy, or inattentive state and there is no such uniform pulsation when the brain is alert.”

Continuous Reaction as a Measure of Attention

BOUT six years ago, the present writer conducted a simple word learning experiment with a small group of children ranging in age from two and a half to four years. The task, in this instance, was to learn to recognize a number of printed words by associating them with toy objects which they represented. At the close of the investigation we found marked individual differences in achievement. We also discovered that these individual differences did not correlate highly with intelligence as measured by the Stanford Binet I.Q. Some relatively dull youngsters with a certain placidity of temperament accomplished more, under the given learning conditions, than other, brighter, children who seemed unable to focus upon the problem for longer than a few seconds at a time. This tendency to distractibility was more marked with the younger subjects but appeared at all chronological age levels. We further noted that wherever this inattentive behavior appeared it had certain fairly well defined characteristics. Movements were mercurial,-particularly eye movements. There was marked diffuseness of energy output, with little evidence of control. Response to the test situation seemed to be, not integrated effort under the direction of a persistent idea, but rather, a series of fairly discrete reactions to an environmental kaleidoscope of stimulus patterns. These observations raised a number of interesting questions in regard to the nature of attention. With this group of children, physical, intellectual and emotional factors seemed to be nicely integrated in the attentive states. What interfered with the coordinating of processes in the inattentive states? Is inability to control attention an organic, an emotional, or an intellectual defect? Does the power to attend develop gradually in small children with measurable increments between chronological age levels? Can attention be measured at all? The following study is an attempt to explore a small corner of this very large and interesting field. It aims to deal with three aspects of the problem: