The Rapid Establishment of Low-Rate Fixed Interval Responding by Humans in a Single Experimental Session

1986 ◽  
Vol 36 (3) ◽  
pp. 357-363
Author(s):  
Teresa F. Doyle ◽  
Herman H. Samson
Keyword(s):  
Fixed Interval ◽  
Experimental Session ◽  
Single Experimental Session ◽  
Low Rate

scholarly journals Acute hypoxia impairs dynamic cerebral autoregulation: results from two independent techniques

2009 ◽  
Vol 107 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
Andrew W. Subudhi ◽  
Ronney B. Panerai ◽  
Robert C. Roach
Keyword(s):  
Cerebral Autoregulation ◽  
Acute Hypoxia ◽  
Latin Squares ◽  
Differential Sensitivity ◽  
Experimental Session ◽  
Assessment Techniques ◽  
Frequency Components ◽  
Autoregulation Index ◽  
Single Experimental Session ◽  
Dynamic Cerebral Autoregulation

We investigated the effect of acute hypoxia (AH) on dynamic cerebral autoregulation (CA) using two independent assessment techniques to clarify previous, conflicting reports. Twelve healthy volunteers (6 men, 6 women) performed six classic leg cuff tests, three breathing normoxic (FiO2 = 0.21) and three breathing hypoxic (FiO2 = 0.12) gas, using a single blinded, Latin squares design with 5-min washout between trials. Continuous measurements of middle cerebral artery blood flow velocity (CBFv; DWL MultiDop X2) and radial artery blood pressure (ABP; Colin 7000) were recorded in the supine position during a single experimental session. Autoregulation index (ARI) scores were calculated using the model of Tiecks et al. (Tiecks FP, Lam AM, Aaslid R, Newell DW. Stroke 26: 1014–1019, 1995) from ABP and CBFv changes following rapid cuff deflation (cuff ARI) and from ABP to CBFv transfer function, impulse, and step responses (TFA ARI) obtained during a 4-min period prior to cuff inflation. A new measure of %CBFv recovery 4 s after peak impulse was also derived from TFA. AH reduced cuff ARI (5.65 ± 0.70 to 5.01 ± 0.96, P = 0.04), TFA ARI (4.37 ± 0.76 to 3.73 ± 0.71, P = 0.04), and %Recovery (62.2 ± 10.9% to 50.8 ± 9.9%, P = 0.03). Slight differences between TFA and cuff ARI values may be attributed to heightened sympathetic activity during cuff tests as well as differential sensitivity to low- and high-frequency components of CA. Together, results provide consistent evidence that CA is impaired with AH. In addition, these findings demonstrate the potential utility of TFA ARI and %Recovery scores for future CA investigations.

scholarly journals Similarities in Metabolic Flexibility and Hunger Hormone Ghrelin Exist between FTO Gene Variants in Response to an Acute Dietary Challenge

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2518 ◽  
Author(s):  
Jessica Danaher ◽  
Christos G. Stathis ◽  
Matthew B. Cooke
Keyword(s):  
Serum Insulin ◽  
Substrate Oxidation ◽  
Experimental Session ◽  
Metabolic Flexibility ◽  
Fto Gene ◽  
Anthropometric Measures ◽  
Polymerase Chain ◽  
And Gender ◽  
Fto Rs9939609 ◽  
Single Experimental Session

The rs9939609 polymorphism of the fat mass and obesity-associated (FTO) gene has been associated with obesity, and studies have also shown that environmental/lifestyle interaction such as dietary intake might mediate this effect. The current study investigates the postprandial hormonal regulators of hunger and indirect markers of substrate utilisation and metabolic flexibility following a dietary challenge to determine if suppression of circulating ghrelin levels and/or reduced metabolic flexibility exist between FTO genotypes. One hundred and forty seven healthy, sedentary males and females (29.0 ± 0.7 yrs; 70.2 ± 1.1 kg; 169.1 ± 0.8 cm; 24.5 ± 0.3 kg/m2) complete a single experimental session. Anthropometric measures, circulating levels of active ghrelin, insulin and glucose, and substrate oxidation via indirect calorimetry, are measured pre-prandial and/or post-prandial. The FTO rs9939609 variant is genotyped using a real-time polymerase chain reaction. Metabolic flexibility (∆RER) is similar between FTO genotypes of the rs9939609 (T > A) polymorphism (p > 0.05). No differences in pre-prandial and/or postprandial substrate oxidation, plasma glucose, serum insulin or ghrelin are observed between genotypes (p > 0.05). These observations are independent of body mass index and gender. Altered postprandial responses in hunger hormones and metabolic flexibility may not be a mechanism by which FTO is associated with higher BMI and obesity in healthy, normal-weighted individuals.

scholarly journals The role of consolidation in learning context-dependent phonotactic patterns in speech and digital sequence production

2018 ◽  
Vol 115 (14) ◽  
pp. 3617-3622 ◽  
Author(s):  
Nathaniel D. Anderson ◽  
Gary S. Dell
Keyword(s):  
Second Order ◽  
Speech Errors ◽  
Experimental Session ◽  
Learning Context ◽  
Speech Error ◽  
First Order ◽  
Sequence Production ◽  
Syllable Onset ◽  
Single Experimental Session

Speakers implicitly learn novel phonotactic patterns by producing strings of syllables. The learning is revealed in their speech errors. First-order patterns, such as “/f/ must be a syllable onset,” can be distinguished from contingent, or second-order, patterns, such as “/f/ must be an onset if the vowel is /a/, but a coda if the vowel is /o/.” A metaanalysis of 19 experiments clearly demonstrated that first-order patterns affect speech errors to a very great extent in a single experimental session, but second-order vowel-contingent patterns only affect errors on the second day of testing, suggesting the need for a consolidation period. Two experiments tested an analogue to these studies involving sequences of button pushes, with fingers as “consonants” and thumbs as “vowels.” The button-push errors revealed two of the key speech-error findings: first-order patterns are learned quickly, but second-order thumb-contingent patterns are only strongly revealed in the errors on the second day of testing. The influence of computational complexity on the implicit learning of phonotactic patterns in speech production may be a general feature of sequence production.

scholarly journals Load Auditory Feedback Boosts Crutch Usage in Subjects With Central Nervous System Lesions: A Pilot Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Federica Tamburella ◽  
Matteo Lorusso ◽  
Nevio Luigi Tagliamonte ◽  
Francesca Bentivoglio ◽  
Alessandra Bigioni ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Auditory Feedback ◽  
Gait Speed ◽  
Physical Therapist ◽  
Case Series ◽  
Experimental Session ◽  
Walking Aids ◽  
Single Experimental Session ◽  
10 Meter Walk Test

Background: Crutches are the most common walking aids prescribed to improve mobility in subjects with central nervous system (CNS) lesions. To increase adherence to the appropriate level of crutch usage, providing load-related auditory feedback (aFB) may be a useful approach. We sensorized forearm crutches and developed a custom software to provide aFB information to both user and physical therapist (PhT).Aim: Evaluate aFB effects on load control during gait by a self-controlled case series trial.Methods: A single experimental session was conducted enrolling 12 CNS lesioned participants. Load on crutch was recorded during 10 Meter Walk Test performed with and without aFB. In both cases, crutch load data, and gait speed were recorded. Usability and satisfaction questionnaires were administered to participants and PhTs involved.Results: Reliable data were obtained from eight participants. Results showed that compared to the no FB condition, aFB yielded a significant reduction in the mean load on the crutches during gait (p = 0.001). The FB did not influence gait speed or fatigue (p > 0.05). The experience questionnaire data indicated a positive experience regarding the use of aFB from both participants' and PhTs' perspectives.Conclusion: aFB significantly improves compliance with crutch use and does not affect gait speed or fatigue by improving the load placed on crutches. The FB is perceived by users as helpful, safe, and easy to learn, and does not interfere with attention or concentration while walking. Furthermore, the PhTs consider the system to be useful, easy to learn and reliable.

Motor Memory: Revealing Conditioned Action Tendencies Using Transcranial Magnetic Stimulation

2019 ◽  
Vol 31 (9) ◽  
pp. 1343-1353 ◽  
Author(s):  
Dominic M. D. Tran ◽  
Justin A. Harris ◽  
Irina M. Harris ◽  
Evan J. Livesey
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Motor Evoked Potentials ◽  
Test Phase ◽  
Experimental Session ◽  
Detection Accuracy ◽  
Action Tendency ◽  
Different Response ◽  
Single Experimental Session ◽  
Action Tendencies

Action tendencies can be elicited by motivationally salient stimuli (e.g., appetitive rewards) or objects that support utilization behaviors. These action tendencies can benefit behavioral performance through speeded RTs in response tasks and improve detection accuracy in attentional capture tasks. However, action tendencies can be counterproductive when goals change (e.g., refraining from junk foods or abstaining from alcohol). Maintaining control over cue-elicited action tendencies is therefore critical for successful behavior modification. To better understand this relationship, we used transcranial magnetic stimulation to investigate the neural signatures of action tendencies in the presence of previously trained response cues. Participants were presented with a continuous letter stream and instructed to respond quickly to two target letters using two different response keys. Following this training phase, the target letters were embedded in a new task (test phase), and we applied transcranial magnetic stimulation to the motor cortex and measured motor evoked potentials as an index of corticospinal excitability (CSE). We found that CSE could be potentiated by a former response cue trained within a single experimental session, even when participants were instructed to withhold responses during the test phase. Critically, attention to the previously trained response cue was required to elicit the primed modulation in CSE, and successful control of this activity was accompanied by CSE suppression. These findings suggest that well-trained response cues can come to prime a conditioned action tendency and provide a model for understanding how the implementation of cognitive control can override action automaticity.

Cognitive Variability: The Ubiquity of Multiplicity

1996 ◽  
Author(s):  
Robert S. Siegler
Keyword(s):  
Individual Differences ◽  
Spatial Ability ◽  
Associative Memory ◽  
Experimental Session ◽  
Identical Stimulus ◽  
Cognitive Research ◽  
Growing Body ◽  
Long Time ◽  
Single Experimental Session ◽  
High Level

No one doubts that immense variability exists at the neural level. Even when the identical stimulus is presented repeatedly within a single experimental session, the response of an individual neuron varies from trial to trial. Similarly, with lowlevel cognitive processes such as association, there is no disagreement concerning the existence of competing units. Models of associative memory, both symbolic (e.g., Gillilund & Shiffrin, 1984) and subsymbolic (e.g., Seidenberg & McClelland, 1990), are predicated on the assumptions that stimuli have multiple associations and that these varying associations influence the way in which we remember. Higher level cognition, however, has been treated differently. Many models are universalist: Everyone is depicted as proceeding in the same way when relevant stimuli are presented. Other models are comparative; they hypothesize different ways of thinking among groups defined on the basis of such characteristics as age, expertise, or aptitudes, but hypothesize a single consistent kind of reasoning within each group. Thus, 8-year-olds might be depicted as performing in one way and 5-year-olds in another, experts in one way and novices in another, people with high spatial ability in one way and those with low spatial ability in another, and so on. The finest differentiations that are typically made within these comparative approaches examine individual differences within people of a single age; for example, reflective 8-year-olds are described as taking a long time but answering accurately on the Matching Familar Figures Test, and impulsive 8-year-olds are described as answering more quickly but less accurately (Kogan, 1983). The main purpose of this chapter is to summarize the rapidly growing body of research suggesting that variability is actually a pervasive reality in high-level, as well as low-level, cognition. To place this work in context, however, it seems useful first to briefly consider some prominent examples of universalist and comparative models of cognition and then to consider why they might be proposed and widely accepted even if thinking is far more variable than they depict it as being. A great deal of cognitive research has been devoted to identifying the processing approach that people use on a particular task. This universalist approach has led to many influential models and theories.

scholarly journals Practice-Related Improvement in Working Memory is Modulated by Changes in Processing External Interference

2009 ◽  
Vol 102 (3) ◽  
pp. 1779-1789 ◽  
Author(s):  
Anne S. Berry ◽  
Theodore P. Zanto ◽  
Aaron M. Rutman ◽  
Wesley C. Clapp ◽  
Adam Gazzaley
Keyword(s):  
Working Memory ◽  
Positive Influence ◽  
Experimental Session ◽  
Dynamic Interactions ◽  
Motion Direction ◽  
External Interference ◽  
Task Instructions ◽  
Delayed Recognition ◽  
Single Experimental Session ◽  
The Impact

Working memory (WM) performance is impaired by the presence of external interference. Accordingly, more efficient processing of intervening stimuli with practice may lead to enhanced WM performance. To explore the role of practice on the impact that interference has on WM performance, we studied young adults with electroencephalographic (EEG) recordings as they performed three motion-direction, delayed-recognition tasks. One task was presented without interference, whereas two tasks introduced different types of interference during the interval of memory maintenance: distractors and interruptors. Distractors were to be ignored, whereas interruptors demanded attention based on task instructions for a perceptual discrimination. We show that WM performance was disrupted by both types of interference, but interference-induced disruption abated across a single experimental session through rapid learning. WM accuracy and response time improved in a manner that was correlated with changes in early neural measures of interference processing in visual cortex (i.e., P1 suppression and N1 enhancement). These results suggest practice-related changes in processing interference exert a positive influence on WM performance, highlighting the importance of filtering irrelevant information and the dynamic interactions that exist between neural processes of perception, attention, and WM during learning.

scholarly journals VARIABLE-RATIO CONDITIONING HISTORY PRODUCES HIGH- AND LOW-RATE FIXED-INTERVAL PERFORMANCE IN RATS

1989 ◽  
Vol 52 (2) ◽  
pp. 167-179 ◽  
Author(s):  
Barbara A. Wanchisen ◽  
Thomas A. Tatham ◽  
Susan E. Mooney
Keyword(s):  
Fixed Interval ◽  
Variable Ratio ◽  
Low Rate
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