Many-to-one Research Articles

The Respondent-Type Matching-to-Sample Procedure: A Comparison of One-to-Many and Linear Procedure for Establishing Equivalence Responding

Stimulus equivalence research is dominated by operant conditioning procedures that require the active responding of a participant to establish relations between arbitrary stimuli. In comparison, there has been relatively little research using respondent-type procedures, which only require the participant to view relations that appear on screen. This presentation describes two experiments using a respondent-type matching-to-sample procedure to examine the effect of the one-to-many (OTM) training procedure and the linear procedure on equivalence class formation. The OTM procedure was extremely effective in generating equivalence responding, however the linear procedure was not. These findings are discussed in the context of previous research comparing the two training procedures, as well as the effectiveness of previous respondent procedures.

Discrimination and equivalence class formation in adults using non-differential and differential consequences

ABSTRACT The purpose of the current study was to (1) compare the acquisition of baseline conditional discriminations in younger and older adults, (2) study the effect of the differential outcome procedure (DOP) on the establishment of baseline conditional discriminations, and (3) compare equivalence class formation in younger and older adults. Twenty-four participants, 12 younger adults (20–30 years old) and 12 older adults (67+ years old), participated in the study. In the conditional discrimination training, we gave the participants a break following 180 training trials, and the experimenter evaluated their progress. Participants with overall 50% correct responses or more after those 180 trials continued with the study as planned, with baseline conditional discrimination presented in accordance with the one-to-many (OTM) training structure and serialized training, followed by thinning of programmed consequences across training blocks before a test for the emergence of equivalence classes. If a participant was still training AB-conditional discriminations when the break was presented, with overall correct responses below 50% correct, the participant was exposed to a DOP to evaluate whether such a procedure may facilitate the establishment of the baseline conditional discrimination. Five participants in the older adult group received additional DOP training trials. The results show that two out of the five participants receiving DOP training established the AB baseline conditional discrimination. Neither of those responded in accordance with stimulus equivalence. Two out of the other seven participants in the older adults group and six out of 12 participants in the younger group formed equivalence classes.

Equivalence Class Formation in Adults with Severe Behavioral Problems

Stimulus equivalence is a behavioral phenomenon that has been related to complex human behavior (e.g., remembering, cognitive functioning, and symbolic behavior). As a rule, people diagnosed with severe mental disorders (e.g., schizophrenia, bipolar disorder) that exhibit delusional and hallucinatory behavior, and disorganized speech have shown cognitive impairment (e.g., processing speed, reasoning/problem solving). Not enough research has analyzed the stimulus equivalence performance in this population. This study aims to investigate the stimulus equivalence performance in adults diagnosed with severe mental disorders. In particular, this study analyzes the many-to-one (MTO) and one-to-many (OTM) training structures effects, and the simultaneous (SIM) and the simple-to-complex (STC) training and testing protocol effects on equivalence class formation in this population. To achieve it, we analyzed the behavior of 18 participants diagnosed with severe mental disorders in three different conditions (Condition 1 OTM/SIM; 2 MTO/SIM; and 3 MTO/STC). Behavior consistent with stimulus equivalence was found in 11 out of 13 participants who had finished the study (5 participants decided to leave before completing the tasks). STC yielded better results than the SIM protocol. No differences were found between MTO and OTM training structures. Implications and suggestions for further research have been discussed.

Demonstration of a highly bandwidth-efficient optical interconnection with symbol division multiplexing pulse amplitude modulation.

A novel symbol division multiplexing (SDM) technology is proposed in an intensity modulation and direct detection (IM/DD) pulse amplitude modulation (PAM) optical interconnection. The SDM-PAM4 symbol is the multiplexing of two standard 3-bit PAM8 symbols based on many-to-one (MTO) mapping, increasing by an extra 50% the line rate compared with a typical PAM4 under the same symbol rate and channel bandwidth. The forward error correction (FEC) based on low-density parity-check coding establishes a mechanism between the codewords of both intra- and inter-SDM-PAM4 symbols, to theoretically support the iterative decoding of symbol de-multiplexing employing an optimized bit-interleaved coded modulation iterative decoding (BICM-ID) system. Furthermore, since SDM evidently reduces the mapping order of the PAM signal, the transmission reliability can be effectively improved by alleviating the impairments mainly caused by fiber chromatic dispersion and Kerr nonlinearity. The experimental results indicate that the SDM-PAM4 can achieve more than 5 dB superior systematic receiver power sensitivity over 10-km single mode fiber transmission, and thus represent an important development in coding and modulation multiplexing techniques for optical interconnection systems.

Polar coded probabilistic shaping PAM8 based on many-to-one mapping for short-reach optical interconnection.

In this paper, a polar coded probabilistic shaping (PS) 8-ary pulse amplitude modulation (PAM8) based on many-to-one (MTO) mapping is investigated for short-reach optical interconnection. By ingeniously assigning parity bits to ambiguities positions, no extra PS redundancy and no complex distribution matcher are required in the scheme comparing to traditional probabilistic amplitude shaping (PAS). The noise distributions after different transmission distances are studied and an optimal clock recovery method for PS signal is proposed to degrade the impact of severe eye skew effect on BER performance. The experimental results show that up to 1.2 dB and 0.8 dB shaping gains are respectively achieved over back-to-back (BTB) and 2-km standard single mode fiber (SSMF) transmission. With the help of the proposed optimal clock recovery method in the PS scheme, the shaping gain is improved from 0.15 dB to 0.4 dB after 10-km transmission. Moreover, compared to low-density parity-check (LDPC) code, the polar coded PS-PAM8 can provide an additional coding gain of 2.2 dB with code length of 256, which proves the performance superiority of polar code in short code length. Therefore, the proposed polar coded PS-PAM8 with low complexity and satisfactory BER performance is believed to be an alternative solution for the cost-sensitive short-reach optical interconnection.

A descriptive analysis of baseline and equivalence-class performances under many-to-one and one-to-many structures.

The purpose of the present experiment was to describe responding as a function of One-to-Many (OTM) and Many-to-One (MTO) training structures and identify baseline performances correlated with the accuracy level in tests for equivalence class formation. Participants were 42 adults assigned to either the MTO or the OTM groups, trained on 24 baseline relations, and assessed on the emergence of three 9-member equivalence classes. Participants in the MTO group presented similar frequencies of responses to each of the comparisons throughout baseline training. Also, the number of trials required to meet the baseline mastery criterion was negatively correlated with test accuracy. Participants in the OTM group presented more variable frequencies of responses to each of the comparisons (participants tended to select some of the comparisons less often than others at the beginning of the training). In addition, the number of reinforced responses to the node presented as a sample during training was positively correlated with the number of correct responses during testing for the OTM group. The experiment contributed to an in-depth stimulus control analysis of baseline and test performances, and its results have implications for understanding potential sources of variability between the training structures.

Adaptive Human-Robot Interactions for Multiple Unmanned Aerial Vehicles

Advances in unmanned aircraft systems (UAS) have paved the way for progressively higher levels of intelligence and autonomy, supporting new modes of operation, such as the one-to-many (OTM) concept, where a single human operator is responsible for monitoring and coordinating the tasks of multiple unmanned aerial vehicles (UAVs). This paper presents the development and evaluation of cognitive human-machine interfaces and interactions (CHMI2) supporting adaptive automation in OTM applications. A CHMI2 system comprises a network of neurophysiological sensors and machine-learning based models for inferring user cognitive states, as well as the adaptation engine containing a set of transition logics for control/display functions and discrete autonomy levels. Models of the user’s cognitive states are trained on past performance and neurophysiological data during an offline calibration phase, and subsequently used in the online adaptation phase for real-time inference of these cognitive states. To investigate adaptive automation in OTM applications, a scenario involving bushfire detection was developed where a single human operator is responsible for tasking multiple UAV platforms to search for and localize bushfires over a wide area. We present the architecture and design of the UAS simulation environment that was developed, together with various human-machine interface (HMI) formats and functions, to evaluate the CHMI2 system’s feasibility through human-in-the-loop (HITL) experiments. The CHMI2 module was subsequently integrated into the simulation environment, providing the sensing, inference, and adaptation capabilities needed to realise adaptive automation. HITL experiments were performed to verify the CHMI2 module’s functionalities in the offline calibration and online adaptation phases. In particular, results from the online adaptation phase showed that the system was able to support real-time inference and human-machine interface and interaction (HMI2) adaptation. However, the accuracy of the inferred workload was variable across the different participants (with a root mean squared error (RMSE) ranging from 0.2 to 0.6), partly due to the reduced number of neurophysiological features available as real-time inputs and also due to limited training stages in the offline calibration phase. To improve the performance of the system, future work will investigate the use of alternative machine learning techniques, additional neurophysiological input features, and a more extensive training stage.

Matching-to-sample performance in older and younger adults

ABSTRACT The present experiment studied the influence of simultaneous matching-to-sample (SMTS) or delayed matching-to-sample (DMTS 0 s) using the many-to-one (MTO) or one-to-many (OTM) training structures on the formation of equivalence classes in older and younger adults. Sixty older adults and 16 younger adults were divided into four groups: (1) SMTS-MTO, (2) SMTS-OTM, (3) DMTS 0 s-MTO, and (4) DMTS 0 s-OTM. All of the younger adults established conditional discriminations, whereas only 35 of the 60 older adults did the same. The SMTS-OTM had the lowest number of trials to mastery criterion for the older adults, and the SMTS-MTO group had the highest number of participants forming equivalence classes. In the younger adults, the differences in trials to mastery criterion were minimal, and there were no differences in the equivalence tests across groups. The older adults had a higher reaction time to comparison stimuli than the younger adults.

A Cyber-Physical-Human System for One-to-Many UAS Operations: Cognitive Load Analysis.

The continuing development of avionics for Unmanned Aircraft Systems (UASs) is introducing higher levels of intelligence and autonomy both in the flight vehicle and in the ground mission control, allowing new promising operational concepts to emerge. One-to-Many (OTM) UAS operations is one such concept and its implementation will require significant advances in several areas, particularly in the field of Human–Machine Interfaces and Interactions (HMI2). Measuring cognitive load during OTM operations, in particular Mental Workload (MWL), is desirable as it can relieve some of the negative effects of increased automation by providing the ability to dynamically optimize avionics HMI2 to achieve an optimal sharing of tasks between the autonomous flight vehicles and the human operator. The novel Cognitive Human Machine System (CHMS) proposed in this paper is a Cyber-Physical Human (CPH) system that exploits the recent technological developments of affordable physiological sensors. This system focuses on physiological sensing and Artificial Intelligence (AI) techniques that can support a dynamic adaptation of the HMI2 in response to the operators’ cognitive state (including MWL), external/environmental conditions and mission success criteria. However, significant research gaps still exist, one of which relates to a universally valid method for determining MWL that can be applied to UAS operational scenarios. As such, in this paper we present results from a study on measuring MWL on five participants in an OTM UAS wildfire detection scenario, using Electroencephalogram (EEG) and eye tracking measurements. These physiological data are compared with a subjective measure and a task index collected from mission-specific data, which serves as an objective task performance measure. The results show statistically significant differences for all measures including the subjective, performance and physiological measures performed on the various mission phases. Additionally, a good correlation is found between the two physiological measurements and the task index. Fusing the physiological data and correlating with the task index gave the highest correlation coefficient (CC = 0.726 ± 0.14) across all participants. This demonstrates how fusing different physiological measurements can provide a more accurate representation of the operators’ MWL, whilst also allowing for increased integrity and reliability of the system.

Probabilistic Shaping 44QAM Based on Many-to-One Mapping in DMT-WDM-PON

We introduce a probabilistic shaping (PS) 44-ary quadrature amplitude modulation (44QAM) based on many-to-one (MTO) mapping into a discrete multi-tone wavelength division multiplexing passive optical network (DMT-WDM-PON) with maximum shaping gain of 0.46 dB. A low-density parity-check (LDPC) based bit-interleaved coded modulation and iterative decoding system is proposed to generate and transmit the PS-44QAM DMT signal without any extra PS redundancy. An extrinsic information (EI) is iteratively used between LDPC decoder and PS demapper to retrieve the PS-44QAM DMT signal including overlapped/ambiguous symbols. The experimental results show that the PS-44QAM DMT signal with improved receiver power sensitivity and system fiber nonlinear effect tolerance can be obtained in the power splitter based WDM-PON. Thus, the corresponding system loss budget can be significantly enlarged in the optical distribution network for the purpose of serving more optical network units.

Tailoring of Painful Stimuli Used for Exploring Transfer of Function

Fifteen college students rated the degree of painfulness of six images showing needle injections to different parts of a human hand. The images were rated on a scale ranging from 1 (not painful) to 5 (severely painful). Next, the participants were trained six conditional discriminations with abstract shapes as stimuli and tested for the formation of three 3-member equivalence classes in a one-to-many (OTM) training structure (AB/AC). The test for emergent relations were followed by training a novel set of stimuli (D) to the A stimuli. The needle injection images rated with the highest and lowest perceived degree of painfulness were used as stimulus D1 and D2, respectively. An image where the needle was replaced with a Q tip was used as stimulus D3 and assumed to be perceived as not painful. The DA training was followed by a matching-to-sample (MTS) test for the formation of three 4-member classes, and the participants were asked to choose one out of three identical bottles with water labelled with the B stimuli. Finally, the participants were asked to rate the degree of painfulness of the B stimuli. The main findings were that the B and D stimuli were not rated significantly different, indicating a transfer of function in the ratings from D to B stimuli. In addition, participants avoided choosing bottle B1 over B2 and B3, but they did not differentiate between B2 and B3.

EMERGENCE OF LARGE EQUIVALENCE CLASSES AS A FUNCTION OF TRAINING STRUCTURES

This experiment compared the outcomes of two training structures on the emergence of three 7-member equivalence classes. Seventeen adults were exposed to the Many-to-One (MTO) and another 17 to the One-to-Many (OTM) training structure. The MTO group trained the baseline relations BA, CA, DA, EA, FA, and GA, and the OTM group trained AB, AC, AD, AE, AF, and AG. After mastering the baseline, a test evaluated the maintenance of baseline and the emergence of symmetry and equivalence relations, under a simultaneous protocol. As a result, fifteen out of seventeen (88%) participants in both groups demonstrated stimulus equivalence. There was no significant difference between groups in the average number of training trials required to learn the baseline relations, nor in accuracy in emergent test trials. The MTO group was characterized by faster response speed in baseline training and test trials. Every participant who failed in the MTO group had persistent errors before four, five, or six out of the 18 sample stimuli during the training, while participants who failed in the OTM group had varied baseline acquisition patterns.

Manual-Observing Procedure: an Alternative to the Investigation of Stimulus Control and Equivalence Classes in Matching-to-Sample

This experiment presents a manual-observing procedure as an inexpensive alternative for investigating stimulus control and establishing equivalence classes in a matching-to-sample task (MTS). To illustrate the procedure, we evaluated the effects of different MTS training structures on observing responses and equivalence class formation. Participants had to press a button below each covered sample and comparison stimuli to reveal the stimulus. Four participants were exposed to two different sequences of the many-to-one (MTO) and one-to-many (OTM) procedures, using the manual-observing procedure during training and testing. The results showed that the manual-observing procedure allowed participants to acquire conditional discriminations and form equivalence classes, suggesting that the use of manual-observing responses in an MTS procedure is a useful procedure to evaluate stimulus control in an MTS task.

Effect of Presenting Baseline Probes During or After Emergent Relations Tests on Equivalence Class Formation

The present experiment investigated whether the interspersion of baseline probes among emergent test trials would enhance the yields of equivalence class formation following the exposure to the One-to-Many (OTM) training structure. Twenty adults were exposed to two test protocols, in counterbalanced order: Simultaneous Protocol with Baseline Intermixed and Simultaneous Protocol with Posttest of Baseline (Conditions MixB and PTB, respectively). The conditions varied in respect to test procedure and stimuli set. Both started by training AB, AC, AD, and AE relations concurrently. Next, a test assessed the maintenance of baseline and the emergence of symmetry (BA, CA, DA, EA) and equivalence (BC, BD, BE, CB, CD, CE, DB, DC, DE, EB, EC, ED) relations. In Condition MixB, all test trials were presented concurrently. In Condition PTB, baseline probes were presented after symmetry and equivalence were assessed simultaneously. All participants formed equivalence classes in both conditions. Condition MixB presented slightly lower yields of immediate emergence (16 participants) than Condition PTB (18). Three out of the four participants with delayed emergence in Condition MixB initially failed in symmetry trials, the other two in Condition PTB failed exclusively in equivalence trials. Condition MixB produced significantly faster correct responses over the first five equivalence test trials. The results support that the OTM training structure is highly effective with normal adults, regardless of the interspersion of baseline probes in the test. Also, these results have implications for conclusions about the relevant variables for the OTM efficacy.

Eye movements during conditional discrimination training and equivalence class formation

ABSTRACT Ocular observing response topographies, as duration and number of eye fixations, vary among conditional discrimination procedures. Such measures have yet to be accounted for as a function of different training structures as the many-to-one (MTO), one-to-many (OTM), or linear series (LS). The present experiment explored differential outcomes in eye movement topographies, as duration and number of eye fixations, during the potential formation of six 3-member equivalence classes—prepared simultaneously and in a sequential training arrangement. Nine college students participated. Results showed that one of three participants, prepared with MTO, OTM, and LS, respectively, formed equivalence classes. Participants who responded in accordance with stimulus equivalence revealed longer fixation durations to sample stimuli and shorter fixation durations to comparison stimuli and, furthermore, fixated longer and more often on correct comparison stimuli, regardless of equivalence classformation. These findings have implications with respect to eye movements predictive value of delayed emergence of equivalence classes.

Minimum cost seed set for threshold influence problem under competitive models

Single source influence propagation based models have been widely studied, but a key challenge remains: How does a company utilize the minimum cost to select a seed set such that its influence spread can reach a desired threshold in competitive environment. One efficient way to overcome this challenge is to design an influence spread function with monotonicity and submodularity, which can provide a nice theoretical analysis of approximation ratio. In this paper, we first propose the Threshold Influence (TI) problem, i.e., selecting a seed set with minimum cost such that the influence spread reaches a given threshold η. Then we present two influence diffusion models named One-To-Many (OTM) and One-To-One (OTO) respectively. On one hand, for One-To-Many model, we prove that the influence spread function is monotone increasing as well as submodular and develop a greedy algorithm with a $(1+\ln (\frac {\eta }{\delta }))$ approximation ratio, where $\delta >0$. In particular, the approximation ratio is ($1+\ln (\eta )$) if $\eta $ is a positive integer. On the other hand, for One-To-One model, we demonstrate that the influence spread function is non-submodular. Besides, a heuristic framework is developed to solve this problem. Finally, we evaluate our algorithms by simulations on different scale networks. Through experiments, our algorithms outperform comparative methods.

Eye-Movements, Training Structures, and Stimulus Equivalence Class Formation

Research on equivalence class formation as a function of training structure has shown that there are minimal differences between the many-to-one (MTO) and one-to-many (OTM) training structures, and that the linear series (LS) is the least efficient. Moreover, some research has shown that an observing response can affect how fast stimulus equivalence is established. The present study utilized eye-tracking to investigate how different training structures affect equivalence class formation and eye-movements to comparison stimuli. Thirty participants were randomly assigned to undergo one of the three training structures (MTO, OTM, or LS) with the aim of establishing three five-member classes. The main findings were that 10 out of 10 participants in the OTM group and seven of 10 participants in the MTO group responded in accordance with stimulus equivalence, and that none of the 10 participants in the LS group did. Furthermore, eye-tracking data showed a reduction in the number of eye-movements during training, which corresponded with the findings of speed or inversed reaction time to comparison stimuli. Eye-tracking data also gave a more detailed analysis of the development of eye-movements as a function of training structure during stimulus equivalence testing.

Talk-Aloud Protocols during Conditional Discrimination Training and Equivalence Class Formation.

The primary focus of the present experiment was to study participants' self-talk during conditional discrimination training and test for the emergence of conditional relations consistent with equivalence. Eighteen adult participants were exposed to either a Many-to-One (MTO) or a One-to-Many (OTM) training structure arranged as a 6-s delayed matching-to-sample (DMTS) procedure. During training and testing, participants were asked to talk aloud. Each trial was divided into three time-windows for recording vocal responses. The first time-window was when the sample was presented, the second time-window was the delay following the offset of the sample stimulus until the onset of the comparisons, and the final time-window was when the comparison array was presented. Overall, participants in the OTM condition talked more than participants in the MTO condition. The participants exposed to MTO increased talking during the third time-window from last part of training to test more than the participants in the OTM condition. For 16 of the 18 participants, talking aloud was less than 55% in the second time-window (during the delay). Conversely, talking in the first and third time-windows were higher than 90% in both groups. Thus, it seems that talking is affected by the shift from training to testing to a greater degree when exposed to MTO than OTM. Furthermore, the data indicate that the participants did not need to talk aloud during the delay to respond correctly on DMTS trials.

Previously acquired cue-outcome structural knowledge guides new learning: Evidence from the retroactive-interference-between-cues effect.

The effect of retroactive interference between cues predicting the same outcome (RIBC) occurs when the behavioral expression of a cue-outcome association (e.g., A→O1) is reduced due to the later acquisition of an association between a different cue and the same outcome (e.g., B→O1). In the present experimental series, we show that this effect can be modulated by knowledge concerning the structure of these cue-outcome relationships. In Experiments 1A and 1B, a pretraining phase was included to promote the expectation of either a one-to-one (OtO) or a many-to-one (MtO) cue-outcome structure during the subsequent RIBC training phases. We hypothesized that the adoption of an OtO expectation would make participants infer that the previously learned A→O1 relationship would not hold any longer after the exposure to B→O1 trials. Alternatively, the adoption of an MtO expectation would prevent participants from making such an inference. Experiment 1B included an additional condition without pretraining, to assess whether the OtO structure was expected by default. Experiment 2 included control conditions to assess the RIBC effect and induced the expectation of an OtO or MtO structure without the addition of a pretraining phase. Overall, the results suggest that participants effectively induced structural expectations regarding the cue-outcome contingencies. In turn, these expectations may have potentiated (OtO expectation) or alleviated (MtO expectation) the RIBC effect, depending on how well these expectations could accommodate the target A→O1 test association. This pattern of results poses difficulties for current explanations of the RIBC effect, since these explanations do not consider the incidence of cue-outcome structural expectations.

Effects of Between-classes Negative Relations Training on Equivalence Class Formation across Training Structures

This study compared three three-choice matching to sample (MTS) procedures on their probability to form equivalence relations for each of the three training structures: one to many (OTM), many to one (MTO), and linear series (LS). All three MTS procedures established the same within-class positive relations, but they differed in the number of between-class negative relations included in their baseline trials, with two in the standard (STD) matching procedure, one in the semi-standard (SEMI) procedure, and none in the altered (ALT) procedure. Positive and negative control baseline relations were assessed by using trials including novel stimuli or a blank comparison stimulus before symmetry and equivalence performance testing. The matching procedures did not differ in the rate of positive control that they yielded, but they did in the rate of negative control. The number of between-class negative relations in the baseline trials was directly related to the probability of equivalence class formation. However, this relation was different across training structures: it was lineal for the OTM structure, did not differ between the STD and SEMI procedures for the MTO structure, and did not differ between the SEMI and ALT procedures for the LS structure. Testing of positive baseline control by means of a blank comparison stimulus as an incorrect choice and testing of the negative baseline control by using novel stimuli as the correct choice proved more sensitive to the matching procedures and most discriminative between participants who formed equivalence relations and those who did not.