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PubMed1994

Implicit retrieval processes in cued recall: implications for aging effects in memory.

Aging produces deficits in what has come to be called explicit or direct memory, in which subjects must consciously retrieve information from long-term memory. In contrast, many studies have shown that when implicit or indirect memory is tested, old and young subjects perform equivalently. The present study manipulated orienting instructions (structural vs. semantic) for indirect (stem completion) and direct (cued recall) memory tasks for both young and old subjects. Contrary to previous research, older subjects produced equivalent performance to young subjects on the direct test as well as on the indirect test, and performance of both groups was worse in the direct than indirect test. In addition, semantic orienting activity at study led to greater learning on the indirect test than structural orienting for both groups, although the levels of processing effect was greater for the direct test. We attribute the unexpected lack of age difference on the direct test to its difficulty, which led subjects to adopt an implicit (generate + recognize) rather than an explicit retrieval strategy during the cued recall task. Because the elderly are not impaired with regard to either implicit retrieval or recognition, this strategy produced equivalent performance in the two groups.

Adult↗
PubMed1984

Need and decision making in dentistry--an economic perspective.

The issue of alternative definitions of need has recently received attention in the dental literature. However, a number of important questions have gone unanswered. Why is it necessary to assess needs; who is to do the assessing and in what decision making contexts are needs to be assessed? This paper presents an economic rationale for assessing needs. Scarcity necessitates choices as to how resources will be used, and it is only by identifying needs and the costs of meeting them that such choices can be made rationally and explicitly. Three levels of decision making are distinguished, together with three assessors of need: patients, dentists and society. It is argued that decisions to seek care and to comply with professional instructions will ultimately rest with patients, whereas decisions as to which individual patients should be given treatment of what type will inevitably lie with the dental profession. In the latter case it is particularly important that dentists' judgements should reflect the social context of their decision making. At a wider community level, it is suggested that dental care professionals have a major role to play in assessing the potential for improvements in the oral health of the population, while the task of making societal decisions as to which needs ought to be met is essentially that of policy makers. Once the legitimate roles of various parties in assessing needs in different decision settings have been established, the concept of need has a key contribution to make to the planning and provision of dental care services.

Decision Making↗
PubMed1988

Is there (sex) life after coronary bypass?

The heart has been regarded throughout history as the central core of life and emotions, of kindness and generosity, courage and grief. Cardiac disease can be overwhelming for both the patient and for the partner, and fear of death is a common and quite normal response. Sexual activity after convalescence is a valuable incentive for patients to undergo rehabilitation. Self-confidence and satisfaction can be greatly enhanced by affectionate closeness, and prolonged foreplay can be savored at any age. Sex play is relaxing and healthful whereas anxious sexual preoccupation, frustration, and avoidance may actually be greater risk factors than the mild physical effort involved for coitus or coital alternatives. Male and female patients with cardiac disease expressed regret that their primary physician, cardiologist, or surgeon had not broached the subject of sexual function before or after the acute illness. They were interested, but both patients and physicians were probably uncomfortable with explicit sexual dialogue. Some common sense reminders to post-MI and post-CABS patients about sexual function may be given verbally or in written form, together with diet and exercise instructions. These should include: a heavy meal or heavy alcohol intake before coitus should be avoided; early morning can be an ideal time for coitus or sex play; moderate room temperature is best; a comfortable sexual position can be found with experimentation; chest pain or palpitations are signals to use appropriate medications; and coital death is rare in a stable, long-standing sexual relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The role of visual attention in saccadic eye movements.

The relationship between saccadic eye movements and covert orienting or visual spatial attention was investigated in two experiments. In the first experiment, subjects were required to make a saccade to a specified location while also detecting a visual target presented just prior to the eye movement. Detection accuracy was highest when the location of the target coincided with the location of the saccade, suggesting that subjects use spatial attention in the programming and/or execution of saccadic eye movements. In the second experiment, subjects were explicitly directed to attend to a particular location and to make a saccade to the same location or to a different one. Superior target detection occurred at the saccade location regardless of attention instructions. This finding shows that subjects cannot move their eyes to one location and attend to a different one. The result of these experiments suggest that visuospatial attention is an important mechanism in generating voluntary saccadic eye movements.

Attention↗
PubMed2001

How many music centers are in the brain?

When reviewing the literature on brain substrates of music processing, a puzzling variety of findings can be stated. The traditional view of a left-right dichotomy of brain organization--assuming that in contrast to language, music is primarily processed in the right hemisphere--was challenged 20 years ago, when the influence of music education on brain lateralization was demonstrated. Modern concepts emphasize the modular organization of music cognition. According to this viewpoint, different aspects of music are processed in different, although partly overlapping neuronal networks of both hemispheres. However, even when isolating a single "module," such as, for example, the perception of contours, the interindividual variance of brain substrates is enormous. To clarify the factors contributing to this variability, we conducted a longitudinal experiment comparing the effects of procedural versus explicit music teaching on brain networks. We demonstrated that cortical activation during music processing reflects the auditory "learning biography," the personal experiences accumulated over time. Listening to music, learning to play an instrument, formal instruction, and professional training result in multiple, in many instances multisensory, representations of music, which seem to be partly interchangeable and rapidly adaptive. In summary, as soon as we consider "real music" apart from laboratory experiments, we have to expect individually formed and quickly adaptive brain substrates, including widely distributed neuronal networks in both hemispheres.

Brain↗
PubMed2002

Testing memory for unseen visual stimuli in patients with extinction and spatial neglect.

Visual extinction after right parietal damage involves a loss of awareness for stimuli in the contralesional field when presented concurrently with ipsilesional stimuli, although contralesional stimuli are still perceived if presented alone. However, extinguished stimuli can still receive some residual on-line processing, without awareness. Here we examined whether such residual processing of extinguished stimuli can produce implicit and/or explicit memory traces lasting many minutes. We tested four patients with right parietal damage and left extinction on two sessions, each including distinct study and subsequent test phases. At study, pictures of objects were shown briefly in the right, left, or both fields. Patients were asked to name them without memory instructions (Session 1) or to make an indoor/outdoor categorization and memorize them (Session 2). They extinguished most left stimuli on bilateral presentation. During the test (up to 48 min later), fragmented pictures of the previously exposed objects (or novel objects) were presented alone in either field. Patients had to identify each object and then judge whether it had previously been exposed. Identification of fragmented pictures was better for previously exposed objects that had been consciously seen and critically also for objects that had been extinguished (as compared with novel objects), with no influence of the depth of processing during study. By contrast, explicit recollection occurred only for stimuli that were consciously seen at study and increased with depth of processing. These results suggest implicit but not explicit memory for extinguished visual stimuli in parietal patients.

Aged↗
PubMed2000

An investigation of learning during propofol sedation and anesthesia using the process dissociation procedure.

BACKGROUND: Many studies have shown that patients may remember words learned during apparently adequate anesthesia. Performance on memory tests may be influenced by explicit and implicit memory. We used the process dissociation procedure to estimate implicit and explicit memory for words presented during sedation or anesthesia. METHODS: We investigated intraoperative learning in 72 women undergoing pervaginal oocyte collection during propofol and alfentanil infusion. One word list was played once before infusion, another was played 10 times during surgery. Venous blood was taken for propofol assay at the end of the intraoperative list. Behavioral measures of anesthetic depth (eyelash reflex, hand squeeze response to command) were recorded and used to adjust the dose of anesthetic where clinically appropriate. On recovery, memory was assessed using an auditory word stem completion test with inclusion and exclusion instructions. RESULTS: The mean blood propofol concentration was 2.5 microg/ml (median, 2.3 microg/ml; range, 0.7-6.1 microg/ml). Mean alfentanil dose was 2.1 mg (median, 2.0 mg; range, 1.2-3.4 mg). Comparison of target and distractor hits in the inclusion condition showed memory for preoperative words only. However, the process dissociation procedure estimates showed explicit (mean, 0.18; P < 0.001) and implicit (mean, 0.05; P < 0.05) memory for the preoperative words, and a small amount of explicit memory for the intraoperative words (mean, 0.06; 95% confidence interval, 0.01-0.10). Memory performance did not differ between the 17 patients who consistently responded to command and eyelash reflex and the 32 patients who remained unresponsive. Blood propofol concentration and alfentanil dose did not correlate with memory for the intraoperative list. CONCLUSIONS: There was no unprompted recall of surgery, but the process dissociation procedure showed memory for words presented during surgery. This memory was apparently explicit but did not correlate with the measures of depth of anesthesia used.

Adult↗
PubMed1994

[Effects of color on implicit and explicit memory tests].

We report two experiments that explore why recent investigations of implicit memory did not find any effects of color information on test performance. The argument that previous failures to find effects of repetition priming were due to an arbitrary association between objects and colors was found to be wanting. To the contrary, both experiments showed no or small effects of repetition for objects paired with their prototypical colors. A second argument according to which subjects attend to the colors at encoding did not fare much better. More importantly, however, we found strong effects of repetition priming with a conceptual implicit memory measure, whereas previous research had relied exclusively on perceptual tests of implicit memory. In both experiments, the subjects were asked to choose a suitable color for each object at testing. No instructions about remembering the objects were given. The results demonstrated strong preferences for the previously seen colors in the color-choice task. Furthermore, this effect was present to the same extent with picture objects and with object names, corroborating the conceptual nature of the implicit memory measure. Finally, we observed many functional dissociations with explicit measures of memory for color information, demonstrating implicit use of memory in the conceptual choice-test for colors.

Attention↗
PubMed2001

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories.

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.

Humans↗
PubMed1987

Planning disorder after closed head injury: a case study.

Disturbances of executive functioning after traumatic brain injury represent significant obstacles to social and vocational recovery and may require specific remedial intervention. We report the treatment of a client with impaired planning ability and poor self-control after closed head injury. Intervention consisted of a self-instructional procedure that required him to verbalize a plan of behavior before and during execution of the training task and gradually faded overt verbalization. There was systematic reduction of off-task behaviors and problem-solving errors over the eight weeks of training. Pre- and postmeasures showed significant changes consistent with increased planning ability. Self-control ratings of everyday behaviors improved with explicit training to promote generalization. Training of plan-ahead and self-verbalization strategies appears effective for remediation of executive functioning after traumatic brain injury. Generalization to real-life situations can be observed with extended training.

Adult↗
PubMed2001

Restriction of task processing time affects cortical activity during processing of a cognitive task: an event-related slow cortical potential study.

As is known from psychometrics, restriction of task processing time by the instruction to respond as quickly and accurately as possible leads to task-unspecific cognitive processing. Since this task processing mode is used in most functional neuroimaging studies of human cognition, this may evoke cortical activity that is functionally not essential for the particular task under investigation. Using topographic recordings of event-related slow cortical potentials, two experiments have been performed to investigate whether cortical activity during processing of a visuo-spatial imagery task is substantially influenced by the time provided to process the task. Furthermore, it was investigated whether this effect is additionally modulated by a subject's task-specific ability. The instruction to respond as quickly and accurately as possible led to increased negative slow cortical potential amplitudes over parietal and frontal regions and significantly interacted with task-specific ability. While cortical activity recorded over parietal and frontal regions was different between subjects with low and high spatial ability when processing time was unrestricted, no such differences were found between ability groups when subjects were instructed to answer both quickly and accurately. These results suggest that restricting processing time has considerable effects on the amount and the pattern of brain activity during cognitive processing and should be taken into account more explicitly in the experimental design and interpretation of neuroimaging studies of cognition.

Adolescent↗
PubMed2005

Voluntary task switching: chasing the elusive homunculus.

In the voluntary task switching procedure, subjects choose the task to perform on a series of bivalent stimuli, requiring top-down control of task switching. Experiments 1-3 contrasted voluntary task switching and explicit task cuing. Choice behavior showed small, inconsistent effects of external stimulus characteristics, supporting the assumption of top-down control of task choice. Switch costs were smaller when subjects chose to switch tasks than when instructed by an external cue. Experiments 4-6 separated choice costs from switch costs. These findings support models of task switching that incorporate top-down processes in accounts of switch costs. The degree to which task switching procedures capture top-down versus bottom-up processes may depend on the extent of environmental support provided by the procedure.

Attention↗
PubMed1974

The effects of explicit timing and feedback on compositional response rate in elementary school children.

The effects of several variables on compositional response rate were investigated in three classrooms. After establishing baseline composition rates in each of the three classrooms, an experimental phase was introduced that consisted of: explicit timing of the children's composition period with a stopwatch, immediate feedback on the number of words each child produced, public posting of the greatest number of words written by each child to date, and instructions to try to exceed their highest score. In the second-grade classroom, these conditions were introduced, removed, and re-introduced. In two fifth-grade classrooms, these conditions were introduced according to a multiple baseline, across classes. In all cases, introduction of the experimental conditions led to a doubling of rate of words written by students and an increase in subjective quality ratings of compositions made by independent judges.

Journal Article↗
PubMed1977

An experience with a systems approach to curriculum design.

Learning system design, based on general systems theory, is a powerful facilitator for planning and implementing programs of curriculum and instruction. Curriculum planners are directed to a practical consideration of all systems components, and an awareness of their interrelatedness. Specifically they must deal with: Problem areas or barriers to success; the need to define and choose explicit outcomes; ways to make the curriculum operational; and a specific plan for program assessment. The systems process is value free and content free. Values are generated as content is selected and fitted into the system components. Therefore the system input is a crucial factor in the quality of the system. I have attempted to share some aspects of systems methodology which were very useful in the experience of designing a program for the education of gerontological nurse practitioners.

Curriculum↗
PubMed2000

From novice to no know-how: a longitudinal study of implicit motor learning.

The aim of this study was to ascertain whether the performances of implicit and explicit learners would converge over an extended period of learning. Participants practised a complex motor skill--golf putting--for 3000 trials, either with a concurrent secondary, tone-counting task (implicit learning) or without such a task (explicit learning). The cognitive demands of the secondary task were predicted to prevent the accumulation of verbalizable rules about the motor task. The implicit group reported significantly fewer rules than the explicit group on subsequent verbal protocols. The performance of the implicit group remained below that of the explicit group throughout the learning phase. However, no significant differences were found between groups during a delayed retention test. Additionally, for the participants in the explicit group only, a Reinvestment Scale score correlated positively with the number of rules accrued and negatively with overall putting performance during the learning phase. We use the results to argue against the excessive use of verbal instruction during skill acquisition, which might be unnecessary and ultimately might hamper performance under stressful conditions.

Adult↗
PubMed2003

Vestibular, optokinetic, and cognitive contribution to the guidance of passive self-rotation toward instructed targets.

We ask how vestibular and optokinetic information is combined ("fused") when human subjects who are being passively rotated while viewing a stationary optokinetic pattern try to tell when they have reached a previously instructed angular displacement ("targeting task"). Inevitably such a task entices subjects to also draw on cognitive mechanisms such as past experience and contextual expectations. Specifically, because we used rotations of constant angular velocity, we suspected that they would resort, consciously or unconsciously, to extrapolation strategies even though they had no explicit knowledge of this fact. To study these issues, we presented the following six conditions to subjects standing on a rotatable platform inside an optokinetic drum: V, pure vestibular (passive rotation in darkness); O, pure optokinetic (observer motionless, drum rotating); VO, combined (passive rotation while viewing stationary drum); Oe, optokinetic extrapolation (similar to O, but drum visible only during first 90 degrees of rotation; thereafter subjects extrapolate the further course in their minds); VOe, combined extrapolation (similar to VO, but drum visible only during first 90 degrees ); AI, auditory imagination (rotation presented only metaphorically; observers imagine a drum rotation using the rising pitch of a tone as cue). In all conditions, angular velocities ( v(C)) of 15, 30, or 60 degrees /s were used (randomized presentation), and observers were to indicate when angular displacement (of the self in space or relative to the drum) had reached the instructed magnitude ("desired displacement", D(D); range 90-900 degrees ). Performance was analyzed in terms of the targeting gain ( G(T) = physical displacement at time of subjects' indication / D(D)) and variability (% E(R) = percentage absolute deviation from a subject's mean gain). In all six conditions, the global mean of G(T) (across v(C) and D(D)) was remarkably close to veracity, ranging from 0.95 (V) to 1.06 (O). A more detailed analysis of the gain revealed a trend of G(T) to be larger with fast than with slow rotations, reflecting an underestimation of fast and an overestimation of slow rotation. This effect varied significantly between conditions: it was smallest in VO, had intermediate values with the monomodal conditions V and O, and also with VOe, and was largest in Oe and AI. Variability was similar for all velocities, but depended significantly on the condition: it was smallest in VO, of intermediate magnitude in O, VOe, Oe, and largest in V and AI. Additional experiments with conditions V, O, and VO in which subjects repetitively indicated displacement increments of 90 degrees, up to a subjective displacement of 1080 degrees, yielded similar results and suggest, in addition, that the displacement perceptions measured at the beginning and during later phases of the rotation are correlated. With respect to the displacement perception during optokinetic stimulation, they also show that the gain and its variability are similar whether subjects feel stationary and see a rotating pattern, or feel rotated and see a stationary pattern (circular vection). We conclude that the vestibular and optokinetic information guiding the subjects' navigation toward an instructed target is not fused by straightforward averaging. Rather the subjects' internal velocity representation (which ultimately determines G(T)) appears to be a weighted average of (1) whatever sensory information is available and of (2) a cognitive default value reflecting the subjects' experiences and expectations. The less secure the sensory information (only one source as in V or O, additional degrading as in Oe or AI), the larger the weight of the default value. Vice versa, the better the information (e.g., two independent sources as in VO), the more the actual velocity and not the default value determines displacement perception. Moreover, we suggest that subjects intuitively proceeded from the notion of a constant velocity rotation, and therefore tended to carry on the perception built up during the beghe perception built up during the beginning of a rotation or, in the case of vestibular navigation, to compensate for the decaying vestibular cue by means of an internal recovery mechanism.

Adult↗
PubMed2003

Age-dependent recall bias for material of internal versus external origin.

OBJECTIVE: To learn whether young and aged subjects exhibit different recall biases for internally derived (Internal) versus externally supplied (External) material. BACKGROUND: Internally derived knowledge, prized by educators and therapists, can bring about dramatic behavioral change. Such information, seldom assessed on formal memory testing, may be preferentially recalled compared with external-origin material. Under some circumstances, however, subjects may demonstrate a recall advantage for externally supplied over internally generated material. METHOD: We compared Internal and External word recall in young and aged subjects with and without explicit intent to remember. RESULTS: Although overall the young and aged subjects recalled the same number of words, we did find a word-origin recall bias. This recall bias differed by age group (P = 0.005). When not instructed to remember words, the young subjects tended to remember more External words, while aged subjects remembered more Internal words. CONCLUSIONS: The differences in the brain mechanisms mediating Internal versus External recall bias are unknown. However, aging may modify an Internal-External memory bias.

Adult↗
PubMed2004

Flexible learning for postgraduate nurses: a basis for planning.

This paper describes a survey undertaken with postgraduate nursing students in a New Zealand University based School of Nursing in 2002 to establish their access to and use of computers and information technology for study. Whilst there is minimal flexibility and use of technology to support student learning for postgraduate nurses in the University's School of Nursing presently, the University proposes increasing flexibility across all courses. This is in part a response to the increased internationalisation of education and developments in technology affecting programme design, delivery and support that can benefit teachers and students. The findings of this survey form a basis for planning the introduction of flexible learning. Results indicate that not all students have convenient access to technology for study purposes, nor are they at the same level in terms of using technology. The implications of the survey for planning flexible learning, including the need to be explicit about requirements for access to technology and upskilling opportunities are discussed.

Attitude of Health Personnel↗