Context affects the numerical semantic congruity effect in rhesus monkeys (Macaca mulatta)

Abstract

Do monkeys anchor their numerical judgments based on the context in which their choices are presented? We addressed this question by varying the numerical range across sessions while macaque monkeys made ordinal judgments. Monkeys were trained to make a conditional discrimination whereby they were reinforced for ordering arrays of dots in ascending or descending numerical order, dependent on a color cue. Monkeys were tested using two ranges of numerosities that converged on a single pair. Similar to the findings of Cantlon & Brannon (2005), we found a semantic congruity effect whereby decision time was systematically influenced by the congruity between the cue (ascending or descending) and the relative numerical magnitude of the stimuli within each range. Furthermore, monkeys showed a context effect, such that decision time for a given pair was dependent on whether it was a relatively small or large set of values compared to the other values presented in that session. This finding suggests that similar to humans, the semantic congruity effect observed in monkeys is anchored by the context. Thus our data provide further evidence for the existence of a shared numerical comparison process in monkeys and humans.

The discovery and comparison of symbolic magnitudes

“…For example, if the presented stimuli are all relatively small animals (e.g., smaller than a dog), then the relatively large animals within this restricted set (e.g., rabbit and beaver) will show an advantage for ''choose larger'' over ''choose smaller'' (Č ech & Shoben, 1985;Č ech, Shoben, & Love, 1990; see also Petrusic & Baranski, 1989). Similar range effects have been observed in studies of comparative judgments by monkeys (Jones, Cantlon, Merritt, & Brannon, 2010). It is natural to suppose that an observer could strategically shift reference points to reflect the magnitude range of the presented stimuli.…”

A delta-rule model of numerical and non-numerical order processing.

“…Furthermore, the semantic congruity effect is context-dependent, meaning that a pair (CD, say), is easier with the instruction “choose larger” than “choose smaller” in a small range (e.g., in the range A to D, where CD is the largest pair); but the same pair (CD) is easier with the instruction “choose smaller” than “choose larger” in a large range (e.g., in the range C to F , where CD is the smallest pair). Again, this is observed both in humans (Cech & Shoben, 1985) and in animals (Jones, Cantlon, Merritt, & Brannon, 2010).…”

Of Men and Mice: Modeling the Fragile X Syndrome

“…Compared to rodents, primates have several advantages when it comes to modeling cognition (for a comprehensive review, please also see “Why primate models matter”; Phillips et al, 2014 ), in particular with respect to ASDs: the cell types and circuits seen in primates are more similar to those found in humans, which is relevant to many cognitive tasks, but particularly important to spatial working memory and social recognition (see Hopkins, 2013 ; Frey et al, 2014 ; Neubert et al, 2014 ; Morecraft et al, 2015 ; Wilson et al, 2015a ; and the section: “The Cortex, the Hippocampus and FXS”) the prolonged prenatal development of the cortex, which is characteristic to humans and primates, is not present in rodents, hampering neuro-developmental studies in rodents group living, co-operative behavior and cultural intelligence are much more sophisticated in primates (cp. the section: “The Cortex, the Hippocampus and FXS” and Decasien et al, 2017 ; Street et al, 2017 ) the basic communication features characteristic to human language are already present in primates, including the ability to utilize symbolization, basic semantic representation, categorical representation and rudimentary grammar (Moore et al, 2003 , 2005 , 2006 ; Joly et al, 2012 ; Morrill et al, 2012 ; Ghazanfar et al, 2013 ; Wilson et al, 2013 , 2015b ) many tests developed to analyze cognition in humans can easily be adapted for primates, e.g., eye-tracking to study abnormal gaze (Machado and Nelson, 2011 ; Rosati et al, 2016 ), a typical symptom of autism spectrum disorders, or computerized cognition tests (Spinelli et al, 2004 ; Harris et al, 2007 ; Barner et al, 2008 ; Diester and Nieder, 2010 ; Jones et al, 2010 ; Takemoto et al, 2011 ; Verrico et al, 2011 ; Beran et al, 2012 , 2015 ; Brosnan et al, 2012 ; Evans and Beran, 2012 ; Basile and Hampton, 2013 ; Klein et al, 2013 ; Bramlett-Parker and Washburn, 2016 ; Oikonomidis et al, 2017 ), thereby facilitating the translation of results …”

“…many tests developed to analyze cognition in humans can easily be adapted for primates, e.g., eye-tracking to study abnormal gaze (Machado and Nelson, 2011 ; Rosati et al, 2016 ), a typical symptom of autism spectrum disorders, or computerized cognition tests (Spinelli et al, 2004 ; Harris et al, 2007 ; Barner et al, 2008 ; Diester and Nieder, 2010 ; Jones et al, 2010 ; Takemoto et al, 2011 ; Verrico et al, 2011 ; Beran et al, 2012 , 2015 ; Brosnan et al, 2012 ; Evans and Beran, 2012 ; Basile and Hampton, 2013 ; Klein et al, 2013 ; Bramlett-Parker and Washburn, 2016 ; Oikonomidis et al, 2017 ), thereby facilitating the translation of results…”