When we think of the cognitive sciences and literature, we usually think of bringing expertise from neuroscience to literary texts. However, interdisciplinary projects of this nature usually focus on semantic fields or narrative patterns, marginalizing the literary quality of the texts that are examined. More recently, the opportunities that come with a focus on aesthetics and poetic form have been discussed following Stockwell (2009), who has argued that we need to go beyond semantics in the field of cognitive poetics. Experiments using fMRI scanners have shown that readers’ brains ›fire up‹ holistically but that engaging with poetry and prose activates different regions of the brain (cf. Jacobs 2015). So one task of cognitive poetics is to look more closely at the aesthetic experience of literary texts. The sonnet is arguably a suitable test case for a cognitive poetics that is interested in form. After all, received wisdom has it that the sonnet abides by a rigid formal pattern: »it is a fourteen-line poem with a particular rhyme scheme and a particular mode of organizing and amplifying patterns of image and thought […] usually [rendered in] iambic pentameter« (Levin 2001, xxxvii). Accordingly, matters of form should play a crucial part when sonnets are read. At the same time, due to its »particular mode« of organisation, the sonnet is often thought to be a poetic form that is prone to cognitive processes. Helen Vendler (1997, 168) claims, for example, that Shakespeare’s Sonnets reflect »the fluidity of mental processes (exemplified in lexical and syntactic concatenation)«. And according to Raphael Lyne (2011, 198), Shakespeare’s sonnets are an »ideal place« to investigate »thinking in a cognitive rhetoric«. Following Vendler and Lyne in their focus on cognitive processes when discussing the sonnet, I will challenge simplistic notions of poetic form that – in the case of the sonnet – are limited to structural features like the fourteen-line rule. Aberrations like the sonetus retornellatus , a sixteen-line sonnet, testify that the number of lines is not a decisive formal feature for the sonnet form. The poetic form, I will argue, is indeed brought to the fore when we focus on the particular internal organisation of thought, and I will point to Shakespeare’s »Sonnet 126«, a twelve-line sonnet, in order to highlight cognitive approaches to the sonnet form. Bringing Cognitive Literary Studies (CLS) to the sonnet form is thus a promising endeavour. We need to make sure, however, that CLS is mindful of rhetorical strategies and logical patterns that inform and form the sonnet. And CLS needs to take into account that mental processes and poetic form are locked into a dynamic process: form resonates with cognitive skills rooted in rhetoric and logic, and at the same time shapes those mental processes. If we accept that poetic form is not given but evolves while stimuli for cognitive processes and emotional responses are provided, research in cognitive poetics must take aspects of form more seriously. In her comprehensive study of poetic form, On Form. Poetry, Aestheticism, and the Legacy of a Word , Angela Leighton (2007, 1) has pointed out that the task for anybody who wishes to conceptualize form in the realm of language is to address its »bent […] towards materialization, towards being the shape or body of something«. As an abstract noun, ›form‹ feigns a static nature while it is, according to Leighton, a process, a cognitive activity. Conceptualizing form as a process, Leighton claims, will »alter the very thing we mean by knowing« (ibid., 27) because it will not allow for distilling knowledge about poetic form as a result of that process. This is very much in line with John G. Bruhn’s and Stewart Wolf’s »The Mind as a Process«, in which they have argued that in the study of the mind a »medical approach« alongside a »laboratory approach« is needed to develop »process-oriented research« (Bruhn/Wolf 2003, 84sq.). Scrutinizing poetic form more systematically with the help of cognitive sciences thus also promises to help us redefine our concept of knowing. Exciting experiments with a focus on affect and emotional responses have brought to the fore the notion that aesthetics plays an important part in the process of reading poetry (cf. Lüdtke 2014). These experiments suggest that schema theory, with its reliance on pre-existing meaningful structures, falls short of grasping the process of reading poetry as an aesthetic process. So while pattern recognition, be it on a narrative plane or a semantic plane, is certainly one facet of the cognitive process of reading poetry, the process involves other facets, too, that CLS has only begun to address. Vaughan-Evans et al. (2016, 6) have perhaps provided »the first tangible evidence that this link [between an aesthetic appreciation of poetry and implicit responses] is permeable«. They argue that the »spontaneous recognition of poetic harmony is a fast, sublexical process« (ibid.) opening up a playing field for CLS at a sublexical level that still warrants investigation. Equally, a recent eye-tracking study of how English haiku are being read, conducted by Hermann J. Müller et al. (2017), has revealed that readers’ individual engagement with poetry becomes more diverse with a second or third round of engaging with the text. This may sound trivial, but it does challenge the notion that CLS will help establish universal patterns of cognition. On the contrary, CLS may corroborate a hermeneutical stance: with every reading of a poem, new questions arise; poems are never fully understood. CLS can thus help to heed Bruhn’s and Wolf’s interjection that »we should pay more attention to the responses of the individual qua individual than averaging individuals into groups« (Bruhn/Wolf 2003, 85).