The motor system in simple reaction time experiments

In this paper evidence is presented that the variability of the motor system does not play an important role in the variability of simple reaction time. Many studies refer to this fact which, however, seems contradictory to electrophysiological data. A model is proposed for the operation of the motor system in simple reaction time experiments which consistently links single cell neuronal activity with electromyographic activity and with response time. It appears that the motor system subserving simple reactions consists of many elements which once triggered produce a mechanical response well defined in time despite the fact that the elements themselves show a rather large time jitter.     

Eyeblink classical conditioning: hippocampal formation is for neutral stimulus associations as cerebellum is for association-response

Extensive evidence has been amassed that the cerebellum, hippocampus, and associated circuitry are activated during classical conditioning of the nictitating membrane/eyeblink response. In this article, the authors argue that the cerebellum is essential to all eyeblink classical conditioning paradigms. In addition, the septohippocampal system plays a critical role when the classical conditioning paradigm requires the formation of associations in addition to the simple association between the conditioned and unconditioned stimuli. When only a simple conditioned stimulus--unconditioned stimulus association is needed, the septohippocampal system has a more limited, modulatory role. The neutral stimulus association versus simple association-response distinction is one of the ways in which declarative or relational memory can be separated from nondeclarative or nonrelational memory in classical conditioning paradigms.     

A general experiment programming system for the IBM 1800

A system is described that meets some user requirements of programming ease, general applicability, and simultaneous multiple S and laboratory operation. The system is based on an extremely flexible time-sharing real-time monitor and a user-level task-oriented programming language which together free the user from all multiple S bookkeeping programming. The conceptually simple language consists of simple commands for operations at the level of experimental procedure, such as displaying stimuli, collecting and timing responses, providing time delays, and recording data. Other commands support string manipulation, arithmetic, and disk I/O. The system is programmed only for the IBM 1800; however, it represents a successful approach to laboratory computerization.     

Procedural interference in perceptual classification: Implicit learning or cognitive complexity?

Researchers have argued that an implicit procedural-learning system underlies performance for information integration category structures, whereas a separate explicit system underlies performance for rule-based categories. One source of evidence is a dissociation in which procedural interference harms performance in information integration structures, but not in rule-based ones. The present research provides evidence that some form of overall difficulty or category complexity lies at the root of the dissociation. The authors report studies in which procedural interference is observed for even simple rule-based structures under more sensitive testing conditions. Furthermore, the magnitude of the interference is large when the nature of the rule is made more complex. By contrast, the magnitude of interference is greatly reduced for an information integration structure that is cognitively simple. These results challenge the view that a procedural-learning system mediates performance on information integration categories, but not on rule-based ones.     

A simple system for displaying alphanumeric characters on an oscilloscope using an AIM-65 microcomputer

A simple system for displaying alphanumeric characters on an oscilloscope screen is described. It may be useful for those applications in which only a few chaxacters should be shown, but within small time limitations. The system, using an AIM-65 microcomputer, is capable of exposure durations below 100 microsec/character. Possibilities of speeding up the system and designing characters are indicated.     

The dynamics of infant visual foraging

Human infants actively forage for visual information from the moment of birth onward. Although we know a great deal about how stimulus characteristics influence looking behavior in the first few postnatal weeks, we know much less about the intrinsic dynamics of the behavior. Here we show that a simple stochastic dynamical system acts quantitatively like 4-week-old infants on a range of measures if there is hysteresis in the transitions between looking and looking away in the model system. The success of this simple three-parameter model suggests that visual foraging in the first few weeks after birth may be influenced more by noise and hysteresis in underlying neural mechanisms than by how infants process visual information after a look begins.     

From simple associations to the building blocks of language: Modeling meaning in memory with the HAL model

This paper presents a theoretical approach of how simple, episodic associations are transduced into semantic and grammatical categorical knowledge. The approach is implemented in the hyperspace analogue to language (HAL) model of memory, which uses a simple global co-occurrence learning algorithm to encode the context in which words occur. This encoding is the basis for the formation of meaning representations in a high-dimensional context space. Results are presented, and the argument is made that this simple process can ultimately provide the language-comprehension system with semantic and grammatical information required in the comprehension process.     

An inexpensive automated system for the measurement of rotational behavior in small animals

A reliable, low-cost automated system for the quantification of rotational behavior from up to 10 subjects simultaneously is described. The system resolves quarter and full turns to the left and right, and can relay data to another computer for statistical analysis. The system is easily constructed from simple and inexpensive components, including the computer, that total less than $1,000 and can be used with a variety of different test chambers.     

Image analysis of small animal feeding behavior: An update

Recently we published a design for an automated feeding behavior system (Rowley, Stitt, & Hanson, 2003). One disadvantage of this system is that it relied on expensive, custom hardware. Here we present a modified version that replaces the custom hardware with a simple, commercially available webcam and modified the MATLAB analysis software as well. The new system is much less expensive and easier to implement, while still providing for bias-free collection of consumption data in a feeding behavior trial.     

Is there manual asymmetry in movement preparation?

Manual asymmetry in response preparation was investigated in simple and complex movements by using simple reaction-time tasks. The simple movement consisted of lifting the index finger, while in the complex one subjects reversed direction of movement to hit a switch after reaching for and grasping a tennis ball. Analysis showed that performance with either the right or the left hand was equivalent, with longer latencies for reacting on the complex task in comparison to the simple one. These findings indicate similar capabilities of the right and the left cerebral hemispheres to prepare the motor system for action independently of the spatial requirements of movement.     

Statistical decision theory and evolution

Two recent articles by Geisler and Diehl use Bayesian statistical decision theory to model the co-evolution of predator and prey in a simple, game-like environment. The prey is characterized by its coloration. The predator is characterized by the chromatic sensitivity of its visual system and its willingness to attack. The authors demonstrate how the coloration of prey and the perceptual system of the predator co-evolve, converging to a Nash equilibrium for both species.     

Heuristic thinking and human intelligence: a commentary on Marewski,Gaissmaier and Gigerenzer

Marewski, Gaissmaier and Gigerenzer (2009) present a review of research on fast and frugal heuristics, arguing that complex problems are best solved by simple heuristics, rather than the application of knowledge and logical reasoning. We argue that the case for such heuristics is overrated. First, we point out that heuristics can often lead to biases as well as effective responding. Second, we show that the application of logical reasoning can be both necessary and relatively simple. Finally, we argue that the evidence for a logical reasoning system that co-exists with simpler heuristic forms of thinking is overwhelming. Not only is it implausible a priori that we would have evolved such a system that is of no use to us, but extensive evidence from the literature on dual processing in reasoning and judgement shows that many problems can only be solved when this form of reasoning is used to inhibit and override heuristic thinking.     

The Dubowitz neurological examination of the full-term newborn

In an ideal world, each neonate should have a comprehensive neurological examination but in practice this is often difficult. In this review we will describe what a routine neurological evaluation in the full-term neonate should consist of and how the Dubowitz examination is performed. The examination has been used for over 20 years and can be easily performed in a short time as the recording sheet provides simple instructions together with simple diagrams to make the recording and the scoring easier. We will also indicate how the examination can be used to identify infants with neurological abnormalities, describing clinical signs which can help to differentiate infants with peripheral neuromuscular disorders from those with central nervous system involvement. The correlation between clinical and imaging findings in infants with neonatal brain lesions will also be reported. Finally we will briefly describe how and when to apply an optimality scoring system in a research setting.     

Assertion,Complexity, and Sincerity

The target of this paper is the ‘simple’ knowledge account of assertion, according to which assertion is constituted by a single epistemic rule of the form ‘One must: assert p only if one knows p’ (where p is a proposition). My aim is to argue that those who are attracted to a knowledge account of assertion should prefer what I call the ‘complex’ knowledge account, according to which assertion is constituted by a system of rules all of which are, taken together, constitutive of assertion. One of those rules—which, following John Searle, I call the ‘preparatory condition’—is of the form ‘One must: assert p only if one knows p.’ All else being equal, simple accounts are preferable to complex accounts. I argue in this paper that all else isn't equal. While the simple knowledge account provides an elegant explanation of certain data, it is hard to see how to integrate the simple knowledge account into a more general theory of illocutionary acts. Because the complex knowledge account avoids this objection while explaining the same data as the simple knowledge account does, I conclude that the complex knowledge account is superior to the simple knowledge account.     

Children's Mechanistic Reasoning

Reasoning about mechanisms is one of the hallmarks of disciplined inquiry in science and engineering, but comparatively little is known about its precursors and development. Children at grades 2 and 5 predicted and explained the motion of simple mechanical systems composed entirely of visible linkages (levers). Students' explanations of device behavior suggested four forms of knowledge: simple recognition of device components, noting of structural relations among components, construction of cause-effect rules derived by observation of regularities in device behavior, and identification of essential system components and interactions among components that accounted for cause–effect rules. Only a few children coordinated multiple essential components to constitute a mechanistic causal scheme. Mechanistic causal schemes, in turn, were associated with successful prediction of the output motion of a system. Device tracing via gesture and talk appeared to support this form of knowledge development, and hence may inform future instructional design.     

Consumers Need Information: Supplementing Teleosemantics with an Input Condition

The success of a piece of behaviour is often explained by its being caused by a true representation (similarly, failure falsity). In some simple organisms, success is just survival and reproduction. Scientists explain why a piece of behaviour helped the organism to survive and reproduce by adverting to the behaviour's having been caused by a true representation. That usage should, if possible, be vindicated by an adequate naturalistic theory of content. Teleosemantics cannot do so, when it is applied to simple representing systems (Godfrey-Smith 1996). Here it is argued that the teleosemantic approach to content should therefore be modified, not abandoned, at least for simple representing systems. The new 'infotel-semantics' adds an input condition to the output condition offered by teleosemantics, recognising that it is constitutive of content in a simple representing system that the tokening of a representation should correlate probabilistically with the obtaining of its specific evolutionary success condition.     

Interactive similarity ordering

The interactive similarity ordering (ISO) system gathers similarity data that can be symmetric, asymmetric, or rectangular in form. Because the subject makes a very simple judgment and the number of judgments is interactively minimized, this procedure can be used for a relatively large number of stimuli. This system has been programmed on a PDP-11/45 and on a Motorola 6800-based microprocessor. An empirical investigation indicates that the ISO system compares favorably with other large stimulus set procedures.     

Graphic bar display of on-line physiological data using a minicomputer,DAC, and conventional servo recorder

A method is described for providing an on-line bar graph display of physiological data. A conventional servo recorder is coupled with an 8-bit digital-to-analog converter, and provides a low-cost, hard-copy graphic display peripheral that can be added to any laboratory type minicomputer system with buffered output data lines. The graphic display technique requires minimal memory allocations and a simple software algorithm to provide a flexible graphic system that can accommodate various types of biological data.     

Content filtering human speech: A simple electronic system

The use of electronic bandpass filtering for content-masking speech samples in studies on expressive aspects of vocal behavior is discussed. A simple electronic filtering system, which can be built easily and which can be adopted readily for a variety of applications, is described.